Facebook's business model I suspect is relying more and more on things like user location. As I recal, there was some blowback from messenger requesting location services in iOS while not using the app. This almost seems like strong-arming users into using messenger perhaps because they are able to extract more user info and metadata due to the additional priveleges. I've never installed messenger, so I may be off the mark...
Not a surprise. I've noticed they've been making the move to Facebook Messenger (which I fathom due to its constant bugginess ) and FB is constantly pushing people in that direction