Technically speaking, even the whole movie would be "cultural misappropriation", since the writers of the plot, and most the cast, aren't polynesians.
Technically speaking, all people with non-English heritage in USA, speaking English, are performing "cultural misappropriation" on a daily basis by simply speaking English.
Also all the people who speak foreign languages are perfoming "cultural misappropriation".
That's why I think that the idea of "cultural misappropriation" should be totally rejected.
I think that Disney, acting in a very stupid way in such case, deserve to lose the earnings from such merchandise.
Just my two cents, as they say in USA: even that's "cultural misappropriation", of course
just like the fact that I'm actually writing in English...