“Map constantly changes - water main break, construction, re-striping, new pothole, the list is endless.”
The data will be updated continuously by input from the fleet of autonomous vehicles. It won’t require starting from scratch, each time something changes.
Even if that were true...and Google is not doing that now and I question whether or not enough radio band exists to do such a thing...what about the first car that encounters the emergency construction zone. How is its map updated? How does it know that a new construction zone sign has been put up to ‘wait for flagman’ if it doesnt even know to look for it?