Because the only season two that fits their narrative would be Aeon, Edge Master, Hwang, and Rock, and there's a good number of problems with this lineup.
Well Edge Master is never in a thousand years going to be DLC character (unless he is just added as a random bonus on top of a season pass that already has four full moveset characters), but those other three are strong candidates for inclusion in a season two, I will grant you. Personally, I believe the second season will be some combination of four from among the following characters, listed here in roughly the order of their likelihood of inclusion: Lizardman/Aeon, a guest character (almost certainly male), Hwang (or Yun-Seong, but not both), Rock, and Li Long. And I think there are plenty of fans of the franchise who would happily pay for that season pass, even if it isn't chock-full of fan favourites. And there's always the potential that some unexpected but highly marketable licensing arrangement for a guest character will pull in / reignite substantial interest from the casual crowd.
you're going to get people who will not be happy with having to buy the other half of Aeon's moveset when it was already in the game.
Seriously, you think that's going to be a bar? What adult human being would be turned off a sale by that fact? First off, as you say, it was half a style and anyway, it was not accessible to the player. Even with a famously finicky / whiny consumer like the video game consumer, that seems far-fetched as something that is going to be determinative of either profitability or whether the devs would want to take that design route.
Then there's Rock, who has all but been assimilated into Astaroth, for all intents and purposes.
Yes, there we are in agreement: the fact that they rolled still more classic Rock moves into Astaroth is a strong suggestion that the dev team did not expect to ever be adding Rock to this game. But as to the broader argument that you express above and here:
They could, for the sake of argument, throw the narrative to the wolves and have a season two that had Yun-seong, Setsuka, Hilde, and Algol in it, but it doesn't make any sense to me for them to do this, instead of just saving those four for SoulCalibur VII. They've come this far, including Cassandra and Amy, taking only the timeline of 1583-1590 into account for characters being included in the game, and they've also not been bending the rules and allowing characters in where they shouldn't be, or "retconning", if you will. They've gone above and beyond to keep the story the same as it originally was, instead of making it work to keep characters/styles like Viola and Z.W.E.I. in, for the extreme example, or Setsuka and Hilde, for the not so extreme example, going against their principle of unique weapons first, even entertaining the idea of having "clones" that they're reworking to make unique instead of just using the unique weapons that they already have.
...I just think you're being (if I can be frank) naive about the realities involved here if you think that they wouldn't be willing to adapt some alternate characters, whether they were perfect fits for the continuity or not, provided they otherwise expected the product to be profitable. I don't think I can more accurately or more fulsomely explain why I think this is an unrealsitic conclusion than I did the last time you asserted this argument in another thread, so I will just partially quote my own response on that occasion:
I think you may be a visitor from an alternate reality if you think there is any chance that they wouldn't be willing to find four characters to fill that roster if they decide a second season is a profitable move. Fighting game developers aren't moving slowly but unerringly towards a serialized bonus content format because it allows studios to fill out their rosters (but only where thematically and narratively appropriate) but rather because it allows the publisher (/typically parent company, as here) to extract a higher return on profit. See, in an industry where consumers have managed to freeze the perceived fair market value of a new release base game for about thirty years, during a period when production costs have sky-rocketed, making the kinds of profits large companies want to see (and to some degree depend upon) becomes harder and harder. Consider everything you have to do for the base game of SCVI, from the coding and production, the design of dozens of characters (the creation and production of their movesets from their design through animation, hitboxing and balance work), work on the basic engine, the creation of many thousands of arts assets including a soundtrack, thousands of modelled items and character features and a dozen levels, engineering the netcode, setting up serverside support and maintaining and patching the system thereafter, licensing, contract, business and administrative costs, initial marketing to get the new entry off the ground and make sure the whole thing is not an entire flop, the list goes on and on and on.
And for all of that Namco gets $60 per unit--for the first year or two anyway, provided the game does pretty well. It's a huge amount of cost and serious risk, even for larger companies. Now consider what they have to provide in a season pass: four characters, one stage, and 100 CaS items. And for that they get $20-30. And they can tailor the amount of content they release in this fashion according to demand as the seasons play out, and ditch further development for a given game at a point where their cost-benefit return is highest. It's way more profit relative to amount of work, time and resources expended, requires a smaller internal staff allocation (freeing up some talent for other IPs), involves a lot less financial risk, and allows for a measured release schedule responsive to market research. They would be absolute idiots not to do it, provided they are confident that they can meet a certain minimal buy-on threshold among the consumer base.
All of which is to say, if there was ever anybody on Project Soul who for some reason suggested they shouldn't do a season two because they couldn't narratively justify four solid characters for a second season (when SCIII alone had 40 playable characters with their own moveset), the Namco execs would make it clear that clueless designer (whatever their position) was not to be invited into any of the meetings with the adults any more. So long as it is profitable, they will keep releasing that content gravy train. It's up to us, as consumers, whether we make that new model worthwhile for them.
...though for what it is worth, I agree that Setsuka, Hilde, Algol and (especially) dampierre are all unlikely picks because of what we know of the development team's design priorities this time around. For the same reasons (among others), absolutely no SCV exclusive character has even the remotest chance of being added, Viola most certainly included. Clearly anybody in the DLC pack has to hit the sweet spot between being a useful character (in terms of both thematics and gameplay) for the design priorities the devs have already telegraphed here (and delivered on in the core product), and also being reasonably acceptable as a part of the aggregate product such that people will pay for it. Thing is, I think you are underestimating how well the characters that fall within the former category will do with regard to the latter. A lot of people would buy an Aeon/Hwang/Rock/Kratos season pass. And for those who won't pay for a season pass, Namco can (and will) sell the characters individually to the consumer, without the price break. They can dice up that content as many different ways as they want and because it is digital content, it costs them virtually nothing to offer additional purchase options.
If we were just talking Namco, yes, they'd absolutely take every opportunity they could to make money. But this is SoulCalibur, the redheaded stepchild, we're talking about here. We don't get the lasting support, even if it means making money, in lieu of other projects. They cut off SoulCalibur V's CaS packs without finishing them when Tekken Tag 2 was on the horizon, even though they doubtlessly would have kept making money by continuing to release more and more parts, because people eat the customization parts up like candy.
Personally, I think this is probably the strongest part of your argument. You're right: sometimes theoretically profitable extensions on content never arise because immediate resources are stretched too thin. And yup, historically (or at least since the mid 2000's) Soul Calibur has generally taken a back seat to Tekken, particularly when a new entry of the latter follows close on the heels of a release for the former. But 2019 is a very different world for development and distribution models than was 2012, and companies are looking to cash in, even as the consumer has become more entrenched on what they want for the buck and whether costumes will suffice. They've clearly got a pricepoint here for a season pass that requires them to deliver genuine content, but because they can package it all together, and because it still represents a huge improvement on their profit-per-dollar-spent-on-development over the base product, there is sufficiently increased incentive to make the effort and increased financial security in pursing this model for a time before rolling the dice on the huge investment of a new entry--and all of these incentives have built alongside the fact that there are now better marketing and distribution systems in place to support sales, and a consumer base that is more amenable (or at least tolerant) of it.
And clearly Namco is an experienced enough player in this market to be responsive to these potential sources of increased revenue with decreased risk by adapting their production and release priorities accordingly--as evidenced by the fact that they have absolutely nothing new announced for 2019 (that I have heard of anyway). Why is Tekken not going to step on Soul Calibur's toes this time (or at least less so)? Because they've planned it that way, and have development teams working on both simultaneously--they've actually gone through a lot of effort to advertise this fact, and it's obvious why. Could sales slumps late in the year cause them to move development back to a core entry for one of their properties? Yeah, quite possibly, but I bet you from herein that two season passes are closer to the average for fighters than one--and eventually major entries will begin to become more serialized, with a little less content delivered at the the start than the previous game each time, and more delivered in increasing numbers of season passes. Because it makes these games once again profitable in a way they haven't been for a while, considering rising production costs and frozen sales prices at launch over the last two decades.
Needless to say, at that point it will become a bit of a push-and-pull between publisher and consumer as to what is a "fair" pricepoint, but being as I get hundreds (if not thousands) of hours out of each Soul Calibur game I buy, I don't personally sweat it, and will keep chowing down on any new characters and stages they offer (and probably most CaS content as well, if it is reasonably priced or they continue to bundle it with season passes--which is why they do that. I'm a little more concerned about the serialization getting too out of hand, to the point where we are eventually getting half the game we used to receive at launch, but consumers will just have to be careful to push back at that point (but hopefully not too hysterically and too soon, such that they undermine the profitability of all season passes--its going to be a difficult balance to strike, no doubt). Now I may not be in all respects the most average consumer, granted. Even so, this is still, as an absolute factual matter, a much more profitable route for them to take, now that the technology is in place and they have slowly conditioned the consumer to expect it. Serialized content is the way of the future for the industry (as with many other forms of media today) and the companies that make fighting games are jockeying to be the ones to first take advantage, because their content is a little more amenable to it than many other genres and their profit-to-expenditure ratio has been in the decline for years, even when compared against other players in the industry.
I have no doubts in my mind that we will get a SoulCalibur VII, the "threat" of this game being the last game meant nothing to me, because if SoulCalibur V couldn't kill the franchise, then SoulCalibur VI won't either. SoulCalibur VI has been doing much better than SoulCalibur V that it wouldn't be nearly as long of a wait for the next game, so instead of looking forward to a season two, we should be looking forward to SoulCalibur VII, not only getting the extra characters, but the game and narrative that supports them.
The absolute earliest you will see Soul Calibur VII is 2025; that's a reality we all need to be quite comfortable with. But I agree that it's all but certain that this franchise isn't going anywhere long-term and that talk of each game possibly being the last is always a major exaggeration.
