I think there are good reasons to not let corporate interests join the space we built to escape them, but I guess every instance is free to (de)federate with whomever they want.
So let’s say my instance (mander.xyz) defederates from Meta but another Lemmy instance that meander.xyz federates with (let’s say “misguided.ml”) does not. What happens when someone from Meta comments on a post from misguided.ml and others from misguided.ml comment on that comment? Will I see the comments on the meta comment, but not the original meta comment itself? Or will I not see the entire thread?
Slightly unrelated, but if you don’t want your content to show up for Meta, unsubscribe from communities originating from instances still federated with Meta. The sunny side of fragmented communities means there are probably alternatives without that downside.
Personally, I find the idea of different versions of a comment section (in text and votes) both fascinating from a technical perspective but also horrifying as a simple user. For various reasons. Sometimes people refer to what’s going on in other parts of the comment section. Or I don’t want to repeat what others already said. This has so much potential for confusion.
So even for users from instances which are federated with Meta, this might be a reason to avoid engaging with Meta. Don’t comment on posts from Meta users, don’t comment on their comments. Your contribution will probably be invisible to most other users.