Throwing a few hundred extra million and every construction worker South of Canada on 24 hour shifts at it to get it done in two years may sound nice here from the cheap seats, but in the real world there is no practical reason to do that. Putting this head to head with Star Wars opening is a bad idea. They aren't going to take attention away, they are just going to bury SNW. Regardless how the final products end up, Star Wars is the bigger deal and will get more media attention. I don't know how much of the Uni/Dis rivalry is real and how much is just message board created, but I'd about guarantee that Nintendo doesn't care about any rivalry. They aren't going to want the opening of their IP land getting buried in the news because it's opening against the biggest IP around. Not to mention, it appears that at least two of the rides will be new tech which has been a thorn in Uni's side. You guys really want them to rush this and have a repeat of Gringotts?
They let Star Wars open, maybe drop some artwork or an opening date as token resistance, but then open Nintendo 6 months later and get the full attention it deserves. Oh, and save a few hundred million dollars and extra man hours in the process, which can go towards opening up something else in the same time frame.