@paulthenerd I can see it going overboard, like with Fortnite (so I've heard); I don't know about MultiVersus but I think the Smash Bros. series has done a good job. I think it is really cool taking a character you know and love and playing as them in a fighting game.
It has actually encouraged me to play some of the game series some of the characters came from.
I do worry about the future, though; if crossovers become too common I feel like characterization itself will begin to become fluffy….