If there is a Mulan III
It would be great if they would showcase more of the actual cultural practices, traditions, beliefs, and the language. I think it'd be great to expose the Western world's children to that, especially considering how quickly China is becoming one of the major powers in the world - very soon they'll be getting their cheap labor over here if we don't watch it - watch for Mandarin to become one of the most demanded languages in the business world (more so than it already is - and surpassing Spanish) in the next 10-20 years. Mark my words. It's happening already. Which is why I've been learning Mandarin for the last year (that and I've been dating a girl from China, which helps).
It's actually astounding how little Americans know about other cultures. I'm actually the only U.S. born person I know of who is not (for the most part) Asian ethnically who actually speaks even a little of an East Asian language. That's a bit sad. It's like people here have a mental block against learning anything outside of English and their own personal sphere of comfort. So I appreciated some of the elements used in the Mulan movies, subtle as some of them are.
I think the 3rd one should focus on family and the importance of that in the culture (far more so than here, believe me - I never see American kids showing anywhere near the respect shown for their families and elders). Just the fact that the last name is used first speaks to that - here, it's very individualistic - all about me, me, me. There, it's about the family and the community and the honor of the family. I like that.