I'm not a lawyer and I don't have a copy of the law, or know what constitutes as a "drone" or "overhead."
But I think Universal might be able to pull something off. For example, it's possible they could say they're not "drones" and instead "controlled balloons," "toys," or "kites" (if they are on strings, directed by a costumed Team Member). They could possibly find a loophole with "fly", perhaps there's a certain height you cannot fly them at (and instead these would "float" slightly overhead).
I dunno, just a thought. But these definitely are not dangerous.