yeah, the whole point of defederation is to not even get to that point. if meta gets far enough ahead that threads users are a majority of your community, you already lost -- they'll just cut you off at some point and everyone not on threads will be forced to get on threads or be left out. that's how they killed xmpp all those years ago.

i hope that enough instances will make that choice that the fediverse survives. we need to learn from the last federation's mistakes to avoid repeating it.