Aang's culture is based on Tibetan Buddhism to a degree, and features him fighting against a large military power attempting to kill or capture him?

Nah, that's probably not it. Might be more how they claimed that Kung Fu Panda was an attempt to cynically cash in on their history and culture, to which they responded by making their own version of the movie.
http://www.cartoonbrew.com/feature-film/chinas-true-response-to-kung-fu-panda-11867.html

>>116899
When asked on /r/thelastairbender someone mentioned that it was the Earth Kingdom and the Dai Li that got the show banned because it's secret police and corruption is very reminiscent of the communist revolution. Tibet had very little to do with the decision.

Since when did this happen? Link?

Or is it just that state-owned television channels are "not distributing it"? They don't distribute a hell of a lot of stuff, Avatar's hardly unique in this respect.

>>116902
You should really consider asking Indy the Great as he's the so-called expert on all things China (don't).

I've been searching for answers for the past couple of nights, but what little I found points to yes.

>>116902
Yeah, I don't think it's banned in China. Perhaps it never aired, officially, in the first place.