First off; what it sounds, The Repository for UOR's HHN seems like the closest we may get to an extreme house (it's best to keep in mind, that while yes; this was tested last year with Legendary Truth; they are now marketing it as an official aspect of their event). It seems very much like that R&D is probably involved; as much as Art and Design would be for Repository. It's just all going to depend on what type of VR Headset they use. If it's limited to a group of four, perhaps they could implement multiple rooms while using HTCVives to the best capabilities..but I wouldn't be shocked if we may see something similar to the VOID VR technology seen in the Ghostbusters VR Experience at Madame Tussauds in NY.
I think one thing is for certain. It shows that Universal Parks and Resorts has interest in the technology; as seen here and at Space Fantasy earlier in the year, so it may not really be much of a shock that events like Universal Cool and Halloween Horror Night's get these experiences well before the main-theme park's get the ability to use it; for fine-tuning the technology.