Anyway, May 13 is fairly recent, but it's two full months before the ship of Firefox 128. I'm skimming this policy and I do not see an explanation of, or reference to, the Ad Measurement feature (am I missing something??)

Did Firefox actually ship, *and enable by default without user notification*, a feature specifically designed for reporting to advertisers via a backchannel what ads the browser has seen, *without first updating their privacy policy to disclose it???*