I don't see any reason that individual Bay Area cities cannot pass laws against Waymo operating there. Why they would do so is a different matter. I'm hopeful though.
0: https://leginfo.legislature.ca.gov/faces/billNavClient.xhtml...
It's simpler than that; cities are wholly created and controlled by the State. California could one day decide to close all the cities and centralize and it would be 100% legal. States delegate their authority to cities.