If a CoA coated G4 attack can still be a punch, then I don't see why CoC coated G5 attack can't be a punch too. The abilities you use to augment your attacks don't change the fundamental nature of your attacks. And I doubt Oda planned on making Dressrosa Luffy fight Kaido. He's quite literally talking about the punches that Luffy will be using against Kaido.