I think in the case of the centralized exchange, they play the role of an escrow and I don't think it will be wrong if it's still referred to as P2P
i guess the definition of p2p exchange already evolved into something what we have today. this is because a lot of scammers are on the loose without the 3rd party escrow. so just like binance, a lot of traders have confidence to trade on this platform because they have assurance that they won't get rekt. i, for one, is more confident on transacting my p2p trades with binance if i want to convert my crypto to fiat. whereas, for other noncentralised platforms, you have your worry that the other party may not release your funds.
I think the point the OP is trying make is that maybe they should try to use another name for it on centralized exchange, that it shouldn't be called P2P, because it doesn't in any way represent it when you consider the definition of P2P.