I can't talk about the Disney side of things, but I can talk the state's DOSH requirements.
If WiFi controls the ride vehicles, if the WiFi doesn't work for whatever reason, the ride MUST switch over to some sort of Safe Mode Immediately. That could be shutting down the ride until it is restored (such as them not moving, though show scenes could still operate), or switching to some preprogrammed mode, such as tracks. The key is 100% reliability and that the vehicles remain a safe distance from each other and other dangers.
So it is up to Disney to prove that to the state. And with a first of its kind system, the state is going to be very picky to protect the safety of the riders.