I'm betting my money on Leap of Faith as one crossover since Lexi Dimante was shown in a picture already.
Since there aren't that many major characters in the first place (parents dead) besides MC, Jaye and Mallory, I'm a little worried, depending on what we're talking about when "a major character will be leaving the story" - temporarily or permanently?
I'm guessing a major event will take place as it was the case in Leap of Faith and will shake up the state of things, that's why we get so many new characters. This sounds interesting, but at the same time it feels risky because the game was mostly about a core group of characters until now