No surprise here. The truth is, even if you are meticulous with your privacy, all it takes is somebody else in the majority of the population to have your details on their device and it’s there permanently. Not to be confused with equally noxious companies like Truecaller, who offer caller ID services by vacuuming up everybody’s address books. However, the author is incorrect, you CAN actually run Android without reliance on Google or Google Play Services, see my guide here.
“Such meta data are also collected by governmental surveillance programs. This kind of meta data is perfect to create user profiles – and will has been used by US military in drone killing operation. And you don’t have a possibility to opt-out from Google’s data collection approach for Android phones.”