You could be right, but I doubt that Lou is. Anyway, my recollection of DHS was that it was a rush decision brought about when the place up the road decided to build and little Mikey decided to rush the construction to get it in before Uni could open. I can't really believe that the first thing they built was Residential Street, but it could be. Anyway, it doesn't really matter when all is said and done. I'm thinking that they took a number of shots of the California place to have all the angles they would ever need for the outside shots. My information came from both a small internet search about dates and, if I recall a "Scoops" article debunking the use of the Florida half building, but if they needed new footage because the original had changed, well, then they might have used it.
Still, the indisputable facts are that Golden Girls hit the airwaves about 4 years before D/MGM ever existed.