It is difficult to say anything about the partners' agreements without seeing them. The problem these agreements exist in the first place. Instead of Facebook writing a Windows Phone app, they had Microsoft write the app and paid Microsoft with users' data.
The difference would be ignored if it hadn't been replicated in the Cambridge Analytica scandal. People are reasonably concerned about how much data Facebook is giving these third parties and how diligently it's ensuring they aren't retaining it.
These concerns are heightened by the existence of these agreements contradicting with (a) the FTC consent decree and (b) Zuckerberg's statement to Congress. It may also be material in the ongoing biometrics lawsuit in Illinois.