I’m speculating on my theory (which is why I’m not being explicit on it), but I want to point out that the first Sinema did not actually get a “house based on a scene.” They took a scene and character (Swamp Yeti) but actually developed a completely different house that could have occurred without the existence of Sinema at all (yetis in the mountains… which is a standalone myth, unrelated to Sinema).
Now, it’s possible Universal took an idea “that wasn’t fleshed out enough for a standalone house” (where Sinema scenes come from) and, during the course of developing Sinema, fleshed it out to a adequate house idea.
But it’s more likely—based on what we saw with Yeti—a new house is it’s own thing that bears minimal direct connection.
EDIT - And there’s nothing in the details I’m hearing that means the house has to be a “western.”