I think it'll take a little while to settle down, but I'd expect the communities to congregate on more permissive, well federated servers. In the short term I'm doing similar to you what you proposed, e.g. having accounts on various servers, but I expect the need for this to go away as things settle down. I already focus on a couple of instances more than others.

I do think that less permissive instances will still thrive though, although maybe not so much for general content. That may change as more granular controls and better tools emerge so it's less of an 'all or nothing' approach to federating.