To speak to the artwork of Mel Chin, I think the projects he was doing were more similar to public works than actual art in their objective state, but Chin seemed to be doing them for the purpose of exploring these different relationships between separate concepts. Rather than focus his work on the message of "value and preserve these dying cultures" the message he expressed was, "I want to explore the relationship between the growth of video games and the death of these tribal cultures."
Just to address what is probably being asked in the original intent of this assignment, art's inherent role as commentary will always serve to influence those impacted by it, especially when the art is perceived as culturally significant, either because of its popularity or because of the nature of its message. We see in Warhol's work that this idea of consumerism and the conflict between "low" and "high" art take hold of American society, for example. Or Ai Weiwei's use of backpacks to speak to the deaths of school children at the neglectful hands of the Chinese government.