I just discovered that Account suspension is a thing.
Still, in this case the suspension will apparently last until Dec 20 '26. This seems to be an unreasonable long time, for all intents and purposes their account is as good as deleted.
Also, by looking at this user's answers, they seem to be useful and well-written. So I'm skeptical that this user might have been such a nuisance to the community as to warrant such a suspension. I tried to find proof of disruptive behavior, but failed.
Shouldn't this process be more transparent? who comes up with the decision? Is there an appeal process? What safeguards are there against mobbing by other users?