Yes, not sustainable in its current form. Remember, within a decade after Lion King (#1 animated film of all time), Disney was forced to pay big bucks to buy its #1 competitor.
The lines are too long and growing. The scare-zones no longer work to deliver scares. It's not sustainable. Keep in mind, as crowded as it's been, that's just HHN fanatics. Halloween not even on gen pop's radar until next weekend.