“And remember, the quarantined domains list can be changed remotely at any time by Mozilla, without needing a Firefox software update.”
Firefox 115 ships a remote list of domains where only extensions “monitored by Mozilla” may run. The Bugzilla ticket was filed as confidential, in an open source project. In testing, uBlock Origin kept running on a quarantined YouTube while StopTheMadness was switched off, and the warning vanishes entirely if the extension is pinned to the toolbar. Mozilla built a two-tier extension store and gave itself the remote.