Can these Linux phones prevent the mobile phone company ( i.e. Verizon, AT&T or the owner of the tower) from tracking you and selling ( or "renting" )
your location information?
The benefit of open source phones in this regard could potentially be additional control over which apps can access GPS or additional visibility into which apps are requesting it. This already exists on closed source phones, but the devs could make permissions more obvious and potentially give more privacy tips if they so desired. Maybe even do something cool like have a red icon on your home screen that warns you may be giving apps too many permissions or if permissions changed without your interaction.
E911 does not mean your phone is using GPS all the time, only while calling emergency services.