Oh, it's worse than that. Mozilla pioneered the FLoC-like method of personal surveillance. You could say that they have acted as Google's skunkworks. If you are using vanilla Firefox then you're already FLoC'd by default, and it's hard to turn off.

Monitoring your browser interactions and then sending the data back to the mothership whenever the browser restarts (eg. an upgrade), with commercial partners deciding what statistics should be gathered, is what Mozilla has been doing in the last few years. You won't find much about it in their privacy blurb though. I think it's a dimension of why they have been consistently losing browser market share.