The Roblox website shows users their “Previous Usernames” on their profile, and if you decide to go back to one of those previously used names, it shows up on that list again.
I would suggest a feature where if you change your name back the the exact same as a previously used one, it doesn’t duplicate on list, as shown from my profile:
Or rather, instead, the ability to hide certain previous usernames.
Some times being able to see the chronological order is a good thing for some people (like myself), and some times you may want to have an old username not visible in the page…