You say that the US just needs to "get with the rest of the world", though it's clear that Disney is a US-based company with a US mindset. You also ignore that Disney is clearly checking the box with a US audience in mind - if they were trying to be globally inclusive they would have had at least one Asian major character (preferably Chinese), or maybe a major character who is Latino. But they haven't. They are checking the box by making the two main characters a woman and a black man. This is a US-driven decision because these two demographics are the most politicized in "culture wars". If Asians complained loudly about being underrepresented in movies (they are), or if Latinos complained loudly about being underrepresented in movies (they are), Disney would likely put them in. But they don't complain loudly.