Aside from blocking the add-ons site, they might block the update servers. Linux wouldn't be affected I think (unless they block rpm, apt... As a whole), but on windows I think it updates from Firefox servers directly.
There are probably ways around it, but it's a burden for the windows users.
I had been using Linux for home and work for the past 10 years, dual booting for games mostly (do basically only to use steam).
Recently I had to change jobs and was given a windows laptop. I couldn't believe my eyes when I saw that the candy crush ad is still present on corporate devices. In a $3500 workstation from a fortune 50. What the hell.
I managed to get a Mac instead. IT is still laughing about me for asking Linux instead