I think it would be a good idea to make sure that if a post is federated, all follow-up posts will reach all of the same places as the original post. How could this be done? No idea. But it's frustrating if you get replies based on outdated information and have to repeat yourself over and over again. Ideally, UIs display follow-ups prominently in the thread, too.
And another note: Please don't take this as me wanting "less community". That's not only not what I'm saying, it's the exact opposite. I want communities to be independent of instances, to empower individual users and give them more options to curate their experience than what they have now.
If people want the same experience as before, then by all means let's add something that replicates it. Add blocklists to communities, curated by the community admins, which users can subscribe to. Why wouldn't this be possible?
And unlike now, this would have so many advantages: People could decide for themselves if they want this by making it opt-in, and they could also have multiple """instance admins""" with the same account. Isn't fedi all about choice? Then this is it!
If you want to uphold the status quo, please ask yourself if you want it because "that's how things have always been."
Just don't hold everyone else back striving for a better experience.
Volpeon 
