It is. Historically speaking, post WWII/Korea destroyers were 4000 - 9000 tons displacement (the Tin Can sailors can, will, and should correct me if I am wrong)
These Zumwalt class “destroyers” are about the same displacement as a Baltimore class medium cruiser (some call it heavy, but I don’t think it was) from WWII.
These are the biggest destroyers ever, and I am surprised they were designated as such.
They need a big platform for the rail gun
At the time the Zumwalts were on the drawing board the Navy was seeking funds to develop the next cruiser. The program was known as “CGX”. It got cancelled. If they had called their “DDX” a cruiser, then their cruiser project wouldn’t have gotten out of the starting blocks.