So the whole thing is kinda weird, because the new terms of use _do not_ give Mozilla any ability to monetize your data. All they do is state that if you give the browser some data the browser can use that data to follow your instructions.
For example, I am using Firefox right now as I type this message in. Firefox will save what I type in my profile so that if my power goes out (or Firefox crashes, which is rare these days but wasn’t always) then it can recover this text when it restarts. It’s always done this but apparently Mozilla’s lawyers now think that this requires an explicit mention in the terms of use. I disagree, frankly, and I think the lawyers who forced this issue are milking it.