"All changes must be ‘opt-in’, meaning the user must take non-default action to enact the change."
Right, just like I "opt-ed" in to Firefox Hello.
I can't even "opt out" of Firefox Hello!
"Uninstalling the add-on restores the user’s original settings if they were changed.
I wish. Just goes to show that they're pushing an uneven playing field where Firefox Extensions are auto-installed, can't be removed, and can break all the rules. But hey, at least everyone ELSE can't break all the rules.
Funny that they won't even apply this philosophy to their own products and services that they are forcing into user installations without an opt-in or opt-out.