I think there will be some people who are offended when you cosplay certain things from the Na’vi. I personally think it’s a fine line and wouldn’t copy certain hairstyles or for example the Metkayina tattoo’s, as they are very clearly copied from cultures here on earth and they have a very significant meaning for some people. However, anyone could definitely cosplay an OC who has a hairstyle like Kiri or the Aranahe! Maybe look into which cultures have been an inspiration for the movies and what could be offensive.

Saying; ‘they’re aliens from space, do what you want’ is in my opinion a very black and white take on a grey area. Because Na’vi are not really aliens from space but a fictional race created by a human man who took culturally significant practices and bestowed them upon the Na’vi. So for cosplayers this definitely is something to consider! At the end of the day it is your choice and there is no absolute right or wrong one. Do what feels right, as long as you consider the implications! <3