To clarify: they have remote assistance teams, but they cannot “take over” and control the car at all. All they can do is things like plotting a path to go around if the vehicle gets stuck. They have no ability to do safety critical interventions, the vehicle is capable of reaching a ‘minimum risk condition’ all on its own.
Uber drivers would also need to be trained to do this and Uber needs to setup facilities for this. I don’t believe this is likely.
Waymo sends physical human drivers to a car if the Waymo driver (software) is stuck. Remote humans can reach into the model to fix e.g. label problems (e.g the driver thinks this is a pedestrian but it's actually a life size cardboard Captain Picard, thus it's not a problem to drive very close to it) but they cannot drive the car.
I can see Uber drivers sitting in front of computers taking over from the autonomous system to provide a pseudo autonomous experience.