EDIT: They spoke to, but IMHO, did not give enough time to, Cory Doctorow and Brewster Kahle. They mentioned Mastodon đź‘Ť, and described the Fediverse while not actually calling it that! A bit frustrating.
I saw a GitHub repo that explained add-ons that are "useless" and add more finger printing. The biggest reason of them being useless was generally the fact unlock origin already has the feature too.
That's not just how fingerprinting works. Any setting on your browser that is not default and any addon makes your browser setup more unique. From my understanding they don't need to access your plugin listing or request settings because they can also do it based off of how the browser behaves. If you disable JavaScript entirely I suppose you wouldn't have this issue though.
Why would librewolf specifically advise that you minimize your extensions to decrease client uniqueness if it had no effect on client uniqueness? Someone's misinformed, and I don't think its librewolf.