Gregory's ServerYou may never hear about that by @mozilla if russia prevent them to talk about that. The fact that mozilla is US based doesn't free them from obeying foreign laws When serving russian users/customers it might have to abide to russian rules the same way a US company must comply with GPDR when serving euro citizens.
In that case mozilla may just have the choice between not serving any russian user at all and leave the market or obey to russian censorship.