@mastodonmigration My understanding is that their AT-based federation has been fully live and open (ie not invite only) since February 22nd. So Musk buying BlueSky wouldn't make much difference, you and any number of your friends could remove your account from his node while continuing to communicate with the same circle you were on, much as if Rochko sold out (yes I know he won't!) to Musk.
Bluesky: An Open Social Web - Bluesky
We’re excited to announce that the Bluesky network is federating and opening up in a way that allows you to host your own data.
Bluesky (bsky.social)