How is it military propaganda? The plot is about a private military contractor destroying an ecosystem for profit, while there is nothing but good things being said about the way of life of the Na’vi.

But dont worry, there are good apples in the military, and the military paradigm is normal, and everything works out in the end, and you can be a good guy in the military, its fine that your bits get blown off because the military cares, and you can transhumanistically plug yourself in to your living war tech, and be the strongman hero at the head of a hierarchy, and win by being the better warring team, and so on.

* plucks first search result about it without looking again * https://recapio.com/digest/the-military-helped-make-avatar-heres-why-that-matters-by-redacted ... stuff like that. (probably). And many other reveals of military ties to production, and analysis of the messaging, available with more thorough websearches on the matter.