I don't think they will use drones for the center hub nighttime spectacular.
Imagine, if you will, each land having their own nighttime thing. Projection mapping Mario running around SNW complete with a showdown with Bowser would be cool. Monsters wouldn't need a show just lots of fog, sound effects like wind, a far off wolf howling, and some streetmosphere. Basically a scarezone lite. The center hub fountain show can just be a top notch fountain show using music like Holtz's The Planets particularly Mars the Bringer War and Also Sprach Zarathustra. Have a channel on the hotel's TVs that plays the music. In Potter, a wizarding duel using $100 million worth of musion, projection mapping, pyro, and SFX could leave Paris in crumbled ruins. HTTYD could have a nightly "character cavalcade" or mini parade with a couple of floats, stilt walkers, fire breathers, and large dragon puppets.