I dont give a shit if they're decapitated. This is a fictional story, not a sporting event. Oda has made it narratively clear that Big Mom is losing.
Yeah, if you read that post, I said Kid and Law would get a rematch, just like Luffy did with kaido. But at the moment, they went all out just to do serious damage to big mom and are subsequently exhausted.
Similar to Luffy, they're going to get KO'd, awaken some advanced haki(probably FS for Law and ACoA for Kid), and then get their rematch and W after CP0 has a shot against big mom