My point is that this really doesn't matter. If they use ActivityPub as-written, both clients and servers can stop Meta content from reaching their feed. If you just find Threads content annoying, you long-press the post and tap "Block Instance". If you're a site admin and have been given a legitimate reason to block Meta for API abuse (eg. poorly-moderated content, spam, advertisement) then you can exercise your defederation power and be within your right.