Well, technically, Fujino never explicitly confirmed anything about Kirito’s corruption meter, did he? The only somewhat "confirmed" endings are the ones he mentioned a long time ago, but since then, he’s changed the story multiple times. So, in reality, all we have is a logical assumption: if the corruption meter isn’t full, we get the "knows nothing" ending, and if it is full, we get the "cuck" ending. But that’s still a weird conclusion for this mechanic, tbh, since the meter mostly represents Kirito’s willingness to cheat himself.