I know absolutely nothing about how Lemmy works but there’s hopefully some way or will need to be eventually a way to remove old posts from a certain instance. For instance if there is illegal content it would need to be removed. Building a good solution for this that could be done optionally in the defederation process would probably be good and will be necessary at some point anyway.
For instance you defederate from a nazi server — you’d absolutely want the nazi posts gone from your server. And legally you’d need to potentially depending on where the server was hosted — and of course other kinds of illegal content and networks.
I’m not sure what the current state of the tools is though.
Things might go bad with federation with Meta and Meta is indeed loathsome and has an awful history and present of being a bad actor — but responding to “You all are operating on emotion” with the bad faith emotional ad hominem response “Why are you so hard for Zucc?” is kind of proving the point.
I think there’s lots of good arguments around being wary of Meta and defederating (and some good ones in favour of wait and see) but the level of discourse around this issue on here is really not great and too much attacking others (and it’s not just you — the post you’re responding to as well was rude too with “you clearly don’t have a clue what you’re talking about”). The absolutist way people are talking and treating people who have other perspectives has made me feel much less positive about the potential for good discourse and community on this platform.