It's an assumption that content was removed, it's equally possible that the base game was granted X budget which it used up, and additional content that the devs know is desired requires additional resources. If the additional budget is granted, it's likely on condition it recoups the extra investment.
The game should be judged in its actuality, which doesn't include DLC. Is SC VI worth the £50 I paid for it without the DLC? IMO, absolutely. That's how I would review it, looking at what is, not what could have been.
Also, planned DLC is a good thing. It shows the game has a future that will be supported by Namco meaning things like balance, performance and polish patches are more likely as well as extra content. I guess I'm biased because SC is my favourite fighting game, so there is that.