It wasn't even that they used the female version of the real Mauri haka, it was that the movements lack any snap in the animation, which causes them to appear lackluster and without energy.
If you land in Ok'Zandu and walk over to where the Zandu are practicing their dance, one of the characters is female. She's a good example of what the female version should have looked like. Her legs are less bent, and her movements are a bit different, but she still has energy and power, there is more movement in her shoulders and her overall body like you see if you watch the actual Mauri women dance. The version we got for our emote just lacks this.