А вот и ответ модератора форума #mozilla по поводу делистинга расширений:

Edward_Sullivan
mods-addons

Hello @zombbo,

As noted in the article someone linked to in this thread previously, we temporarily restricted access following a request from Roskomnadzor. Notification to the developers of the impacted extensions was not completed in a timely manner and we are reviewing our processes to ensure this does not occur in the future.

https://discourse.mozilla.org/t/the-censorship-circumvention-extension-has-disappeared-from-the-russian-version-of-mozilla-addons/130914/26