I don't think it is true that this rock art is an example of significant culture that has never been censored or expurgated. The taboos and rules which apply to viewing this art and/or reproducing it or the linked stories are surely analogous to a form of censorship. The fact that people have broken those rules does not change this.
It's true that various sites are considered the stories of particular groups ( men V. women, these people V those people) .. but aside from that specific consideration they haven't been censored in the sense of ( painted over | black barred | altered ) or hidden (cave | over hang moved or draped with a false rock).
The major thrust of this sub thread has been about line of original purity more than an obligation for [some group] to openly share to all regardless so forgive me if I still consider these a good example of unaltered works painted on and carved into stone.
I think you are splitting hairs. Control of certain forms of art or literature so that they can't be revealed to all is what we're talking about. The culture in question is very different from ours so we can't expect their taboos or censorship to have exactly the same forms that we might associate with censorship (mean-looking guy with eyeshade and red pencil, hooded monks chained to desks in candlelight, omnipresent super-computer says no, etc).
For example, some stories are not just 'the stories of particular groups' but are not allowed to be told by, or in some cases told to, other groups.
Besides this, how do you know that none of these works have been painted over or hidden?
