Renaming the DoD does directly contradict the National Security Act of 1947, which renamed the Department of War to the Department of the Army, and put it under the newly named Department of Defense.

The National Security Act of 1947, as amended on August 10, 1949, establishes the name of the executive department overseeing the military as the Department of Defense.

Great.

Where does it prohibit alternative names?

That would be a significant free speech violation, so it doesn't.

However, the idea that an "alternative name" should be espoused by the executive branch means that they do not believe Congress should set the name of the department. Which is a point of contention, as Congress set the name about sixty years ago. The act was already amended for a rename in 1949. The problem isn't the name. The problem is the idea behind renaming it unilaterally: the idea the President has more authority than Congress.

No, I should point out new accounts that are objectively wrong that are trying to stir up division and hate.

As should you, if you weren't in a similar position to them. Which it seems like you are?

Your comments are all flagged, dead, or downvoted to irrelevance in this thread, it’s clear you’re wrong, go get educated.