Lost access to VS Code Marketplace publisher after email provider migration - same e-mail address

Thanks for the details.

Unfortunately, Visual Studio Marketplace publisher ownership cannot be recovered or reassigned manually by users once access is lost (expired PAT + inaccessible email domain). There is no self-service option to reassign a publisher to a new account, even if the author is the same.

The only supported option in this scenario is to contact Microsoft Visual Studio Marketplace Support and request a publisher ownership recovery. Microsoft may verify authorship and, at their discretion, either restore access or advise creating a new publisher.
If Microsoft cannot recover the publisher, the extension will need to be republished under a new publisher ID, as Marketplace publishers cannot be force-transferred.