I don't think it's Beetlejuice because, following up on clue I posted months ago, word from a soild source is WB pulled the plug because they didn't want the house associated with a super-spreader event. (This was last Summer.)
I also agree with
@RevFreako, Universal doesn't
need a weekend crowd, and a house wouldn't necessarily deliver one anyway.
But what about an after-hours event? Maybe open 1 or 2 more original houses plus Bride and Tooth Fairy. Universal has a history of things like this--most notably final B&T, but also private tour of Halloween house after screening the movie, the time they opened Hogsmeade after Potter 8, etc. Make tickets free on BrightEvent, guarantee yourself a 4-hour block of super-fans and try to sell the as much beer and blinky cups and food as you can, maybe mark down merch to unload it as well. Should bring in revenue--even though the parks are at capacity, given the crowd I bet revenue is down--and makes the super-fans feel special, ready to come back next year. This is a long shot, but it's the only reason I see to open an extra house or two.