Twitter's official position is that accounts/usernames are not assets of their users (this isn't an Elon-era argument, from what I understand). I found this out when they argued in Alex Jones' bankruptcy hearings that his account should not be repossessed/auctioned off, an argument Alex supported since that's where he's been moving his audience over to to keep the cash rolling in no matter what happens.
https://fortune.com/2024/11/27/x-twitter-elon-musk-account-o...