> What a CLA usually does is grant perpetual permission to do anything with the code, including to relicense without asking. Practically speaking, CLAs grant full ownership to a single hand.
What CLAs do, is explained in the first half of the sentence. What it means in practice (in the context of talking about relicensing) is hence what "practically speaking" means.
Anyway I've edited it to avoid using the word "ownership", which might confuse the intended meaning.
No, they don’t. CLAs don’t transfer ownership.