Alphabet would have to approve the proposal in the "coming weeks," and there's no guarantee that it'll work even if it gets the all-clear. City development frequently involves billions of dollars. Sidewalk would likely have to ask cities (if not larger governments) to chip in, and that's assuming that they're willing to put the fate of a district in the hands of a private company. If the firm can persuade everyone to give it a shot, though, you might see how smart cities work in practice without waiting decades for all the technology to fall into place.