This is a good observation. That said, I have always thought of the name change as propaganda in the line of many things we are not intended to think about clearly. I'm also reminded of the warning President Eisenhower gave about the military industrial complex.

Department of War is far more accurate though I am sure plenty of people that still believe in the liberal world order hate it. I'm not a Trump supporter but one thing of value he has provided is forcing the establishment types in both parties to expose themselves. He doesn't sugar coat stuff. He's not an honest man but he doesn't have pretense. He has no shame. Republicans and Democrats of the past have looked nice and talked nice while they command the war machine to kill people.

I'm of the opinion that I'd rather have a brute that sounds like a brute than a slick guy in suit that is pleasant but is actually a brute as well. So, to me the name change is a re-framing towards what the department of defense actually is.

I mean, why was the war department named this in the first place? Using your analogy these were people just describing the purpose of the department. I believe it was formed in 1789. Long before the modern era of propaganda. We have to be careful not to lionize the politicians and military industrial complex of the past because of WW2. War Is a Racket and there are critics of the war machine like Smedley Butler even in the 1930s.

But, I agree with your conclusion that this is also marketing/framing to make the US seem tougher. But, I'm not opposed to the rename.