Stop spreading fake news. The app was literally called Facebook Research - I know you want to believe that there was a lot of hiding going on but it is really not the case.
Go visit https://play.google.com/store/search?q=facebook&c=apps&hl=fr . Are you able to tell which apps are supported by facebook and which are not ? For example, "onavo protect" is about 80th in the list, who in their right mind would think "yup, this one totally owned by facebook".
I wouldn't ever think that anything called "Facebook XXX" is a facebook app, even more so if it's clearly sold by a shell company. It was hiding, even though it was ironically in plain sight.
I know you want to believe the worst about Facebook. But it doesn't change the fact that the app was literally called Facebook Research and when you downloaded it had Facebook logos all over it - to make it clear that the app was from Facebook. Dive deeper, get data and then make arguments vs. having your feelings take the better of you.