You can now unlink your email address from a two-factor enabled GitHub account in case you’re unable to sign into it or recover it. When the worst occurs, and a user is unable to find an SSH key, PAT, or a device that’s been previously signed into GitHub in order to recover their account, they may want to start fresh with a new GitHub.com account. Since accounts on GitHub are required to each have a unique email address, though, locked out users can have difficulty starting a new account using their preferred email address.
In the 2FA recovery flow, a new option is presented at the bottom of the page, which will allow a user to remove their email address from a GitHub account:
Selecting this option will send emails to each of the addresses on file for the account, each one containing a unique link. Following the link will remove the respective email address from the GitHub account, making it available again for a new account.
For more information, see Unlinking your email from a locked account.