Good point. I checked the page it should be on, and the switch has disabled it. I checked also https://www.mozilla.org/en-US/privacy/firefox/#lawful-bases and it smells like Firefox is selling its users out.

Specially bits like this: "This data may be shared with our advertising partners on a de-identified or aggregated basis."

Apologies for my previous defense of Firefox. I can't find a reason to defend them anymore.