Facebook didn't have to write this paper. They could have done the research and held onto it. They could have not bothered to do research at all. To me, this says that they're willing to do sociological research regarding the implications of their platform, and to share it publicly.

It might be an unpopular opinion, but I think this shows transparency, a certain sense of social responsibility, and at the top level some semblance of understanding of the scope of the effect they have on society.