I think that when the developers started implementing RBF, they used a very misleading word as a verb to this procedure. Double spending is prevented using a peer-to-peer network as the whitepaper says, but they chose that phrase as the proper one for RBF. Maybe a better formulation would be re-broadcasting or broadplacing?
The term used to describe RBF transaction is a correct term and not at all misleading. Double spending in bitcoin simply means spending the same transaction output more than once in different transactions. The term itself doesn't have any indication of success of the act.
1. You can double spend outputs in an already confirmed transaction
2. You can double spend outputs in an unconfirmed transaction without RBF
3. You can double spend outputs in an unconfirmed transaction with RBF
#1 is obviously rejected by
all full nodes. #2 is rejected by
most full nodes and #3 is accepted by
most full nodes.