The solution to that, which I would fully support, would be for kbin, lemmyworld, etc to deferate from threads from the beginning. You can't lose something you never had and personally, I don't want to interact with a meta owned product so the prospect of what you just described bothers me. If lemmyworld doesn't defederate from them I would 100% move to another instance that does.

Edit: So there is actually a pact for instances to sign pledging to block meta and I don't see lemmy.world on it. That said, it's a long list and it's manually updated so I may have just missed it. https://fedipact.online/