Carriers already serve the decisive-battle strategy

Would more Japanese carriers become a larger part of the Kantai Kessen strategy?

They would strengthen the pre-battle attrition phase, but carriers were already integrated into the wider strategy that culminated in the decisive battle.

Kantai Kessen names the climactic engagement within a wider Japanese naval strategy. Carrier aircraft already had a major role in weakening an enemy fleet before that engagement. They also participated in the decisive battle itself. More flight decks would strengthen both roles within the existing plan.