Reading things like this https://moglen.law.columbia.edu/CPC/archive/cyber-archive/msoft/pubtactics-aol-messaging.html
Actually puts the whole idea of Meta Threads and openness front in center. Instead of Meta trying to connect directly with X, they created something which connects to the whole Mastodon system.
Will Meta try to connect to BlueSky who knows. But bluesky connecting to threads would not need anything special. So BlueSky is AOL here ...