It's a rare case, I read your post in 2019, for me there's no difference.
I also think I've come across posts of that user and never suspected it to have been hacked. I may have not paid too much attention but account hackers like to go underground and not post in general forum boards. The signed message provided is a big enough proof that the op here may be the actual owner of the account, question is if they lost it to a hack or sold it. Account tagged till the ownership is settled.
I think it's more fitting to be in Reputation? Since it's not an appeal for a ban, and neither a scam, it's more about one specific account and the situation surrounding it.
The user is also asking for a means to get their account back, meta could get the faster attention from the recovery team.