It's not a rumored connection. It's speculation. A rumor requires someone saying something definitive about it happening or not. I'm just looking at the likely IPs and connecting dots. (While this point may seem like semantics, it's vital to differentiate between rumor and speculation. The last couple of years, too many "this would be a good idea" posts got turned into a "this is happening" confusion. All that does is disappoint people.)
That said, you may get one original house that actually fits the common thread. You might get a zone. The fact of the matter is that, historically, the "commonality" between houses doesn't exist beyond IPs and anything to pull the originals into it is forced. In 2008, the marketed idea was that all the houses were based on urban legends/Mary Agana's treatments, but we got Interstellar Terror. In 2009, they were "all movies" except they weren't. They just put the house designs on movie posters. All of the 2011's "the houses are all based on bad luck" concept was a hackneyed failure. The original content is, essentially, created in a vacuum. That's why it's so good. They work to create the best event they can with a variety of houses and zones. While there may be a loose idea of what connects them, it'll come down to whoever designs the advertising to make it "official." Regardless of what is "official," something will not fit. A few things won't fit. (Like AHS, if it happens, won't fit).
I could see this happening, though I wouldn't like it. It would give them an easy megahouse while saving money. The other IPs I was crossing fingers for a megahouse are, at this point, far less likely.