Considering they fill their seats with Season Tickets holders and have a mile-long waiting list...yes they would, because there wouldn't be 30 seats available.
I think they are trying to manage the tour/scalper industries. They are giving season ticket holders the opportunity to buy a few extra tickets for families and friends before they open up group sales. You'll be able to buy those 30 seats next week right? That's still before the general public is able to buy them, right? It's not like they will never sell you 30 seats...