You need to understand your exposure, and who your adversary is. Is it big corps? Hackers? Oppressive governments? NSAs?
What I’m saying is if you’re trying to hide stuff from the last two, you shouldn’t have anything encryptable that they can get to. Keeping that information digitally and not clandestinely is not good.
If you’re trying to not get tracked online by Google that’s an entirely different approach.
The deal is they kill you, you are not that valuable to them in the end. If you are, you wind up at a black site with some guy who’s not in the military.
That’s my take too - it’s probably not a big deal but damn Mozilla, do better in the rollout of a change like that.