Yay, let the spec begin! Just IMO.
M3gan seems like a no brainer for a house, she is pretty much a modern horror icon now, and more importantly super popular.
Five Nights at Freddy's seems like a good fit, super popular, not sure if the amount of large animatronics would be a challenge, but Quiet Place and Monstrous had plenty.
Universal Monsters - just a matter of who, I'd say. I'd like to see a one-character house, Wolman is on the horizon, who knows.
Latin America Monsters - seems to be a yearly event now, again a matter of who. Maybe a zombie Cheech Marin.
Who know what surprises we'll get. A Quiet Place was a surprise this year to me.