Renaming a user account can leave the profile url slug unchanged

[HelenWDTK]

I renamed a user account using the admin interface, and the public url for the user profile remained the same, leaving no way to change the original url.

I was expecting the url to change, and the old one to either not work, or appear as a slug that I could then delete.

The user was a former pro user, who had made over 1,000 requests.