1 year suspensions are not handed out for first offenses. The guidelines for mods are to give escalating suspensions for 7/30/365 days, so this is most likely at least the third suspension for this user.

This case could be different. Do you know he was suspended before? It makes sense that they'd want to ban him for a year if this is retribution. It all checks out. The email doesn't mention a previous ban which I'd expect to be mentioned if it was a factor.

This specific user has been suspended multiple times on different sites of the SE network. I don't know exactly how often.

I received a 1 year suspension on Meta for:

* I asked a question about a moderation policy (are we allowed to delete comments? here are two conflicting sources. Which one is correct?)

* A moderator requested an edit in a comment, then shortly after, deleted it due to not having that edit.

* Since there's no way to edit a deleted question, I posted it again with the edit.

I think the ban was actually for questioning SE's inconsistency. Like all dictatorships, they punish you for not obeying in advance.