Have authorization for when you change your username.
I've accidentally changed my username. And I didn't even click on "Save Changes". And normally say you changed your password, e-mail, etc. for that account. You would have an e-mail sent for authorization to make sure it was you. So if you accidentally or someone changed your Twitch username. Instead of waiting 6 months to re-claim your Twitch username. You would get an email to authorize that change to the username.