The major problem here is that they already somewhat revealed this “feature” but keep details hidden as if they were “top secret”.

This will now get “shit talked” to the sky and beyond and all that Mozilla had to do to prevent this is adding one or two sentences why this feature is good for their users.

Doesn’t look all that silent to me?

Seems to be much ado about nothing currently. Even in the release notes it clarified that this feature is not yet included and the quarantine list will be shared once ready (and will at first be mostly test domains). The blog seems to be wildly speculating on its intended use and possible impacts given the knowledge currently available