AFAIK, there are Florida regulations that prevent you from flying drones around large gatherings (or businesses that would have large gatherings) in Florida and places like UOR or WDW fall under that.
But there's no real ban on flying drones around land where there's no expectation of privacy. Yes, the Universal land is owned by a corporation, but they don't have a basis for privacy like other types of businesses might (i.e. Lockheed or a defense contractor). This is just amusement park/hotel/commercial zoned land; there's nothing there that would cause somebody to get in trouble for flying a drone around while the land is being built.
It should be okay to fly drones around the new land for the next 2 years I'd imagine. Things will probably start getting restricted there around 2021-2022.