I'm going to just come out and say this since I've heard it from two sources now and have been given the clearance to say so, and that's that Talim is slated to be in the game.
Based on research and surveys, Talim is very popular with people that only play single player content and did not purchase or have actually even played many Soul Calibur games since II, and some rarely play fighting games. But they really love the character, and a character that has a strong following can't be overlooked, and was another one of the main factors of criticism towards SCV's roster.
Her return in Soul Calibur VI is due to a combination of these factors, most notably and obviously having topped that character survey back in 2015.
When you want to win back the casuals and get them interested in your game, even if it's something like a character, logic would normally dictate that you listen to it. And they did.
In my own experience, I have noticed that most Talim fans are kind of very specific and have their different sectors, but the commonality is her being very popular with casual fans. I've personally met a great deal of people who like and played Soul Calibur throughout the years that, for various reasons, be they male or female, just really liked Talim. So bringing her back is a great move all around, whether people like her or not, or question her inclusion due to past viability.
However, it's what they decide to do with her that's the most curious to me....
Speaking solely about Soul Calibur V, I recall that there was quite a lot of fan curiosity regarding Talim aging 17 years for that back then (being 31 years old on there, had she been on it) but that obviously didn't happen as she wasn't on the game at all, which was still to the day an odd move due to her age being only 16 prior to SCV, so that would not have been an "issue." I will come out and say I don't know why they didn't use her on V.
Maybe they were afraid to age her? I'm not sure.
Maybe they had thought aging her would somehow kill her appeal?
Which isn't the case at all because people were very engaged and curious trying to imagine what she'd look like as an adult and a full blown wind priestess, which her design could have reflected.
I am personally intrigued how they will go with her. If they will feel they have to retain her "image" as being the "kid" of the series still, or just make her a short adult.
I'll tell you right now that I was not told anything in regards to her age yet, and how they will be handling that, hence why I'm discussing this, and likely to create a discussion because of that for people analyze and talk about until I, or we find out.
But I personally hope they take the shot and don't fall back on some kind of excuse like "wind magic" or some kind of time travely Astral Chaos stuff or whatever to explain why she looks the same as she did on IV, and is still only 16 years old.
I feel like that would be regressive and stunted, as the character needs forward evolution at this point to make a more triumphant return because it would be even more emotionally impactful for her fans to see her return and have changed, to some meaningful extent. One that doesn't lose fans, but makes more.
Like I have said, I don't know if they will be doing that yet, but I would approve of that more than keeping her as she was.
So I will take the personal stance of saying that it would be far more interesting to see her mature into her role as a wind priestess.... and be better tier wise to placate her fans and help create new ones for the character, and additionally have some moveset tweaks to express the character development and age.
I will furthermore state that I would be genuinely surprised if they bring her back after winning that character poll, and don't decide to get her some serious spotlight in the happenings of the story to sustain her fans by making her quite important in the game's story to some extent.