If I had to gamble now, I'd predict a lighter event that is nearly all gauntlets and scare zones. Seems to be the easiest and most plausible option that is doable with the state guidelines that have been given.
It's unclear to me if the mazes that use a tent are considered "outdoors". If they are, then they could probably do a larger event if they wanted.
Of course, the big issues are, as some have already brought up: 1) Is it worth it for USH to do a haunt with such limitations on capacity, and, more importantly, 2) Can the performers and team members be given safe working conditions?
I'm hoping and anticipating a lighter event, but also won't be surprised if nothing happens at all. It really could go either way.