IMO, the most likely result is one or more large, heavily connected meshes centered around an ideological middle ground of significantly online people (probably

IMO, the most likely result is one or more large, heavily connected meshes centered around an ideological middle ground of significantly online people (probably divided by liberal/conservative ideology), sparsely connected to somewhat more fringe instances (maybe a socialist instance that doesn't restrict overt calls to violence, but is still largely ideologically acceptable to the average liberal), and some archipelagos/unfederated instances of even more fringe social groups. And that's a good thing. Individuals get to choose servers that align with their views on moderation and morality, server moderators only need to deal with occasional maliciousness rather than trying to walk a fine line of tolerance, and your social group isn't at risk of being disrupted by a billionaire moving in and blowing it up.