Wow... can't believe I've already been an HHN fan for a whole decade. Silent Hill was the first HHN house I ever went through (Hollywood though, tragically). I would absolutely die if they revisited a Silent Hill house, but stuck to the games instead of the movies. I don't think that will happen until either a new game comes out or a new movie, because as it stands the franchise is kinda... dead. It pains me to say that, since SH is my favorite horror IP of all time.
I really don't think a Demon Slayer house would be as bad as people seem to think, if done right. You'd have to drop the anime aesthetic and make the demon designs a bit more grounded and realistic, but the strangeness of the designs and the gore could end up being pretty scary. The same applies to an Attack on Titan house. I actually think Attack on Titan would work pretty well since it genuinely is a horror IP. They could use the giant head puppets similar to what was used in La Llorona in Hollywood (not sure if Orlando has ever used them). It would also be pretty cool to see a few scareactors on bungee cords like in The Fallen or on a cable like the witch from the Deadly Ever After façade to be soldiers with ODM gear. You'd probably have to focus more on the human-on-human violence and use the Titan puppets sparingly, though.
Do I actually think either of these properties are likely? Not at all. But it's fun to think about, and I would love to see them.