old name forwards to new name.
After a user changes their name, the old name forwards to the new name until the old name has been recycled for reuse.
Reason: Some cases exist where it is not feasible to spend the time to change all old links to the new link such as in youtube descriptions.
Matlauk shared this idea
Its Invis commented
Can you explain more because I think they fixed this, but I might be wrong.