Apple seems to be getting serious about apps sending location data without user consent. Over the course of the past few weeks, Apple has sent developers emails if their apps are in violation of two key parts of the legal section of the App Store Review Guidelines. Those have to do with the sending of location data to third parties without the users explicit consent to do so.
The sections in question are 5.1.1 and 5.1.2, both in the legal part of the guidelines. Those sections of the guide call out data collection and transmission guidelines which is what Apple is cracking down on with these apps.