Waymo may discover that heavy equipment (large fire trucks can easily push Waymo out of the way if it can find somewhere to push it to) WILL move the cars (at least if there is no one in them at the time) in such cases. I recall the scenes during recent wildfires where abandoned cars were blocking roads and a skip loader was just picking up the cars and dumping/pushing them to the side of the road/over the edge - causing extensive damage to some of them.

Decades ago I recall talking to a fireman expressing a question of what happened if there was a car blocking their access in an emergency and he made it clear that the bumper on the front of the truck and the truck's healthy diesel engine would usually take care of the problem very quickly.

I wouldn't cry for waymo if a bunch of their cars got bulldozed out of the way but that's still unacceptable since it slows down emergency vehicles and first responders.