Or it could be both. Time will tell.

ConcernedApe's next game is also built on MonoGame, so he has self-interested reasons to want MonoGame to continue to be maintained. But just because ConcernedApe has self-interested reasons to donate doesn't necessarily mean that it doesn't also come from a charitable place.

MonoGame is basically getting a sponsor. The ecosystem benefits. I'm personally happy to leave it there rather than asking for moral purity.