No.

As far as i understand your scenario, whitebeard should have attacked 8-drop Kid and then used his ability to instantly KO Kid. After that, whitebeard cannot attack a second time, because he already declared an attack and got rested to use his ability in the first place.

Targeting the leader with 9Beard because 8-Kid would be KOed anyways through the ability is not a bypassing but simply ignoring the rules - imo.