Better German naval AA faces better attackers

Would heavier German naval anti-aircraft guns materially change the war?

They would improve shipboard defense, but the aircraft attacking those ships would also be more capable after three additional years of development.

Improved German anti-aircraft weapons could make attacks by older aircraft more costly. The delayed-war premise also changes British and American aviation, so the comparison cannot freeze the attackers at their 1939 standard. Fairey Barracudas, for example, could enter service with the engine originally intended for the design instead of passing through repeated wartime changes. Better defenses would confront better aircraft, leaving no one-sided advantage.