No it isn't. The name was set in statute by the National Security Act of 1947 (as amended in 1949); as with many if not most of Trump's regal decrees, changing it would require an act of Congress, not mere executive fiat. Don't obey in advance.
Lol, dude whatever. Your framing of it as tyranny I reject, it's so stupid. What are you obeying? The name on the building says. Your rebellion is pretty powerful
So all it takes to overturn federal statute is an authoritarian decree and maybe some signage changes then? That's not how any of this works and you should know better. It's more than a name change anyway; it is indicative of sweeping philosophical change in the defense and intelligence communities as a whole.
Do you live in a country where the rule of law has already been thoroughly destroyed and rule by fiat is the norm? I don't! It is still possible to turn things around here, and this means resisting any instances of fascist bullshit, big and small. The name has not been changed by edict just as the 14th amendment and a zillion other laws have similarly not been changed. Do not just accept and accommodate their assertions of arbitrary and unbounded power -- do not obey in advance (e.g. see the excerpt of some rather decent writing on this notion here https://timothysnyder.org/on-tyranny)
You quote lit on surviving 20C authoritarianism because the admin changed the name on a building. Department of War. A sign update is suspending the 14th amendment? Gasping hyperbole everybody knows is nonsene. If you say 'fascism' when it's a PR rebranding you are just abusing actual victims of fascism by trivializing them, you are not saving the republic - tho at least you tried