No, its not; not that the implicit equation of “how it used to be” with “how it ought to be” is valid to start with.
> We had a War Department. Rebranding to Defense was a PR move to hide what was really happening.
No. We had a War Department that was the agency responsible for the Army, including what was then the Army Air Forces, and a Navy Department that was the agency responsible for the Navy including the Marine Corps. Splitting and rebranding the former to the two Departments of the Army and Air Force was done to simultaneously more accurately reflect its responsibilities and to address the growing significance of air power.
This split was simultaneous with the old and now split up War Department and the old but keeping its name Navy Department being subordinated to the new consolidated military establishment named the Department of Defense, but the Defense Department wasn’t a new name for the War Dpartment, it was the name for a completely new thing placed above the older, separate military departments.
We had a War Department. Rebranding to Defense was a PR move to hide what was really happening.
This is a good thing as it’s far more truthful.