How else can they milk the fanbase for money if they just make all their characters available at launch.

10 characters, in my experience, is about as small as a roster can be in a fighting game before it feels like you’re seeing the same matchups over and over again. That might be a bit worse in a 2v2 game, but there are other reasons, like Vanguard, that I’d argue are more compelling reasons to avoid 2XKO.