we have introduced a new back-end feature to only allow some extensions monitored by Mozilla to run on specific websites for various reasons, including security concerns.
https://support.mozilla.org/en-US/kb/quarantined-domains
From this it is not even clear what those some extensions monitored by Mozilla are at this point.
Some is certainly not all.
What if Mozilla decide to disable uBlock (or some such) on some specific websites.
We are in the dark!