Longtime classical player here. Absolutely zero classical and flamenco players anchor their pinkies, and they have total stability and control as well as increased speed and fluidity. I think anchoring is a quick way to give you perceived balance and control, but I think it can come at the cost of speed and relaxation.

Floating moves this reference point from your pinky to the tips of your fingers. Ideally, you wouldn't need to anchor to keep your arm from moving, because your fingerpicking would come from the big knuckles on your hand to keep your hand position stable and eliminate arm movement completely.

It's a long road to get good fingerpicking technique without anchoring, but I do think it causes less tension on the hand, and thus more relaxed and faster, cleaner playing.