Who cares if they reuse the world of sprites, too, BTW? I wouldn't be surprised if a lot of the UNIEL characters have to have elements totally redone to fit alongside ASW particular animation style.
This will actually be an ASW (+French Bread!) game that could have an insanely satisfying size cast on first blush, thanks to all the recycling / relativity minor touchups needed. And we know from right here that we're getting enough RWBY characters (which are all totally new sprites) for it to be considered on equal footing with all these other series that have larger cast to draw sprites from.
I wouldn't be surprised to see a single GG character get sprite'd (again!) to fit into this game, too, but not enough of them to count as a core part of the feature cross.
I wonder if this game will have ISM-style system select, or just bind everything together? As similar as some of these games look to the untrained eye, they have a lot of variety in play, and we'll get something refreshingly new with all of it brought to fight against each other.
Oh, and I hope we get some of the UNIEL musicians making themes for this game.