I don't know, the park has seemed really dead set against having Potter open for HHN. What makes you think they'll change their mind next year? If they did open it, they'd have to have the attractions open as well... guests would be royally pissed to get into the area but not be able to ride anything.
I agree I think it'd be cool if DWT was used as a screening room for either classing horror films, or even CryptTV. If they're not going to add another maze or show, they need to find other ways to move crowds.
There is one way HHN could easily boost maze counts... reuse old mazes. Knott's has been doing it for years. Part of me feels HHN puts itself a bit in a box by having to completely reinvent it from scratch every single year, and I feel like we see the strain of that by the overuse of the same props year after year in different settings, as well as the black walls.
That said, I'm well aware AvP was reused, and it didn't go well the 2nd year. And maybe HHN doesn't want to copy Knott's model, which is fine--I do see the pluses and minues of that. But then again, they've reused TWD for how many years now (the daytime attraction), and are counting that in their maze total--so in a way, they've already been doing it, and we've all just been turning a convenient blind eye to it. That's staffing that could go to another maze instead. Say what you will about Knott's, but for all those mazes over all those years, essentially none have had any black walls at all (unless it was an intentional effect, like the black fuzzy walls in Tooth Fairy).
Instead HHN insists on being completely new year after year. It's a very noble goal, but it gives us the problems we all complain about here.