Possibility of Microsoft buying Facebook is not unthinkable. Microsoft is already an investor in Facebook. Both HoloLens and Oculus are already moving in the same direction with enterprise play.
1. MS doesn't need to sell my data to make their services profitable.
2. MS could merge Facebook and LinkedIn so I could have a person and professional identity in a single app and switch between my networks! I don't have a FB account at all right now).
3. What's App could tie into the existing messaging infrastructure and work for Xbox or Personal Teams messaging.
4. MS could replace the Mixed Reality platform with Oculus. I use Mr for VR and the software kind of sucks and many games don't have MR controller bindings by default, though that's less frequent nowadays.
Microsoft though, collects a huge amount (telemetry in Windows) and is leaning more heavily into ads in the core product.