Yeah they wont get see the un-anonymised data but they will be able to see a pass is moving around. For example our apps (my works) report as a new random identifier each install with iOS, I would imagine a pass being assigned would be similar. I would think they could see if it was different accounts without actually seeing the account, but I dont know.
I personally don't think it would ever come to that at least not now anyway, I bet clubs like Utd and Liverpool monitor this, I just didn't want to say it as a matter of fact.