> Until trademark laws come into play, and you find yourself obligated by law to give up your domain username to a big corporation.
This wouldn't be a big deal in practice (besides losing the domain). Domain usernames are just the combo of you telling Bluesky "I intend to use this domain name" and then you placing a TXT record on the domain to prove you own it. If you want to change domains (or, are forced to), you just give them the new domain name and you set another TXT record (just like if you had set up a domain name as a username for the first time). The underlying DID is still yours.
This wouldn't be a big deal in practice (besides losing the domain). Domain usernames are just the combo of you telling Bluesky "I intend to use this domain name" and then you placing a TXT record on the domain to prove you own it. If you want to change domains (or, are forced to), you just give them the new domain name and you set another TXT record (just like if you had set up a domain name as a username for the first time). The underlying DID is still yours.