“Following recent regulatory changes in Russia, we received persistent requests from Roskomnadzor demanding that five add-ons be removed from the Mozilla add-on store,” a Mozilla spokesperson told The Intercept in response to a request for comment. “After careful consideration, we’ve temporarily restricted their availability within Russia. Recognizing the implications of these actions, we are closely evaluating our next steps while keeping in mind our local community.”
As Mozilla, you probably don't have much choice. What's the alternative? Get yourself banned? How is that better? At least this way, locals can use Firefox despite not having access to those extensions. And people find clever ways to get those extensions anyway, so it's the lesser evil I guess?