Are Xavier and Yvonne going to be back in the next game?
>ITT: Morons who don't realize the playable character (whether male or female) is a separate idea-entity from the rival character (whether male or female).
Xavier/Yvonne are the same idea-entity, with the separate rivals Calem/Serena being the same idea-entity.
>b-but that's just your headcanon!
No, it's not. It's how every game has worked up to this point, and how the characters were shown in promotions leading up to the game. Xavier/Yvonne for pc, Calem/Serena for rival.