I was an early adopter on many platforms, and used the same three letter handle on each. I've had the same thing happen to me, even with an account that was being actively used. There's nothing that you can do about it. It's their platform and they can grab your handle if they want it.
Really kind of weird with all these people who think it is just fine for services to take over accounts of people.
Of course, they can literally do whatever they like, it is their platform.
But it would be nice if everyone considered what it would be like for a platform to just arbitrarily nuke their account one way or another.
There's probably a lot of "well they wouldn't do that, I don't have a valuable named account, and I'm a user in good standing" but in reality they can do it for whatever reason they like and there's no actual guardrails--so anyone's account is equally at risk if they decide to.
