It’s been here since more than a year. https://blog.mozilla.org/en/mozilla/firefox-androids-new-privacy-feature-total-cookie-protection-stops-companies-from-keeping-tabs-on-your-moves/

It’s there on mobile. Check the details tab in tracking protection. You should see it mentioned there.

Is there a non paywalled article somewhere? It asks for a sub the alternative asks for sign up and free trial.

Firefox could get litigated for ad fraud and these trusted 3rd parties could block firefox from accessing the sites. It won’t work.