This is exactly how Waymo works as well. And so did GM’s Cruise before they shutdown. Ithink that if a car gets stuck or confused it can pull over (if possible) and phone home, get some hints as to what to do and continue on its new route if able. If it has to shutdown they probably send a driver and arrange for a new car for passengers.
It makes sense that this is how it would work for any robotaxi service
Mike