It will disable incremental updates but as long as there is a flashable zip file of the full image you can update using that

You can also quickly unroot then do an incremental update and then use magisk to create a flashable boot image afterwards to re-root

From what I understand it doesn’t work on any of the mobile apps which is unfortunate, but I guess that is the price we pay for not wanting to just use the web browser

This update doesn’t seem to remove any add-ons specifically but turns them off on more sensitive websites if Mozilla has not reviewed them.

It does look like there is an about:config option to turn it off, however it looks like this is most likely to be for bank websites etc. and only for add-ons not reviewed by Mozilla.

Currently, at least, ublock origin and most of the bigger adblock add-ons are reviewed by Mozilla and shouldn’t be affected

I know at least at the start some users were confused by the federation process and created 10+ accounts to “subscribe” to other instances plus there have been bots signing up through smaller instances without capcha or email verification so that might explain the discrepency