I have no idea what — if anything — this YouTube clip indicates, but I do think folks need to move past this idea that Horror Unleashed somehow precludes anything from being at Hollywood HHN.
There is logic behind "Vegas is close to L.A., so they can't have the same houses, because they'll cannibalize each other." But that same logic would also suggest that everyone going to Vegas is somehow also going to Hollywood HHN, or vice versa, and that's absolutely not the case.
Vegas gets people from all over the world, and they're primarily coming for gambling, resort/luxury experiences, restaurants, and unique entertainment, which is where HU comes in. Universal can't (and won't) assume that Vegas tourists will somehow pass on visiting HU just because there are similar houses at Hollywood HHN.
It'd be like the In-N-Out in Vegas not doing Animal Style because they'd be worried it would disincentive people going to the L.A. locations.