It's also a bit weird to basically say it can't be 9A because its actually just technical and weird, rather than only hard pulling. That is still a critical component part of what makes a climb 'hard' and if you are good at technical/weird climbing that is just another 'strength'. Otherwise we would all just measure grip strength or do weighted hangs or similar and be done with it.
I think he's just being modest. He knows its nails and knows everyone else knows its nails so he can carry on playing it down until Bosi repeats it and upgrades it. ;D