Unpopular opinion but defederating Meta is a terrible idea. What are people thinking will happen? Allow them to federate and you’ll have mastodon users able to view and interact with posts from Threads without needing to be concerned about ads or tracking, without giving over any more control of privacy than they would to any other fediverse instance, and without needing to possess accounts homed within the Meta infrastructure.

Defederate them, and anyone who wants to interact with anyone on threads will most likely need to maintain a presence on both and handover more personal data to Meta than they otherwise would.

Defederating is actively hostile to fediverse users.