Hi again. Yes, I agree you should ask me, it wasn't as easy to find as I first thought, but here[1] is a thread on HN that discusses it and a bit down the thread you find a link to the Verge [2] which in turn links to the case papers [3].

I admit the links I found now are less clear than I though and I don't have more time now, but there is clearly reason to be suspicious when 1.) Facebook stops encrypting data before upload 2.) Google accept to keep the data without counting it against the users quota 3.) sources claim there was a deal. None of these three carries too much weight on their own but together they paint a picture that something is going on.

[1]: https://news.ycombinator.com/item?id=28485312

[2]: https://www.theverge.com/2020/12/17/22180258/google-whatsapp...

[3]: https://www.documentcloud.org/documents/20428869-the_state_o...