Here is an apparent update. Looks like Google is backing away a bit, but as you stated, where you are is public as long as you are in public:
There is also quite a bit of info that we think of as private, that is not.
Retailers you buy from and banks who handle your CC or debit can sell information about your buying practices. Whether or not you have a cell phone on your person doesn’t change that ability.
Google will change this, and get the same or similarly valuable info some other way.