Changing Username and Mentions

[vegetagz6]

It came to my attention that, we are allowed to change our usernames in nodebb. When we do that, all the mentions in our previous username loses their profile link (becomes inactive). Is it possible to prevent username changes in the ACP? Here is a image showing my previous username (rahul-ramesh) without links, below.

Moreover I registered via Facebook, so I am not sure how this username change is reflected in the database, I mean will I be again able to register new account via same Facebook account?

[julian]

All of the SSO plugins will persist properly throughout username changes. The email if provided will be used to associate the account upon registration, but is otherwise unused.