I don't think they actually unsubscribe you. They basically sit in front of your incoming email and don't pass on emails that match specific patterns. (And apparently sell that sweet, sweet anonymized data)
>Instantly see a list of all your subscription emails. Unsubscribe easily from whatever you don’t want.
So, probably makes sense for them not to unsubscribe so they can still get any info on you but to the layman, it would seem they unsubscribe you from emails.