I would argue that the "fleet destroyer" didn't stop being a "fleet destroyer" during WW II simply because the gunline lost it's former supremacy in fleet tactics. It was still necessary to protect the fleet against a number of threats and perform several new functions (such as plane guard duty)...
Where do you get this rubbish? Perhaps you could reference some citations that support this erroneous assertion?
According to Russell Crenshaw (who served as gunnery officer aboard the USS Maury during WW II) in "South Pacific Destroyer", US destroyers could, and did, open fire at 17,000...