A super-battleship Prince of Wales under air attack

Would Japanese aircraft focus more heavily on Prince of Wales if she were a 70,000- to 80,000-ton super-battleship?

Yes, although the larger ship would probably carry more defensive firepower as well.

A 70,000- to 80,000-ton Prince of Wales would be a larger and more attractive target for Japanese aircraft. The same increase in size could also support more anti-aircraft firepower. The counterfactual therefore changes both the attacker's target priority and the ship's ability to fight back.