Hubris, man.
What I was told was, basically, Universal was talking with Dimension/MTV to use Scream while A&D started designing/building the house. The rights to Scream, from the beginning, looked like a lock. That's why A&D went ahead with it. Problem was, there was never confirmation on WHICH Scream to use. Universal (as an entity) was so confident they could reach an agreement to use the film. It seems obvious, but while A&D was building a house based on the movie (because that's what they wanted to build), the rights holders were only interested in the TV show. When Dimension/MTV refused to budge on it, it was too late.
So, from my understanding, there never was an AGREEMENT for Scream. It was all presumption because, "We're Universal."
Again, that's what I've been told. May be wrong. However, knowing what I know about how a lot of decisions are made, it wouldn't surprise me if that's exactly what happened.