It’s not unethical to comply with the law in foreign countries and, while I obviously don’t agree with China’s censorship, they can point out lots of poor human rights abuses on our end yet Chinese companies are expected to follow our laws here too.
Apple is just doing what any rational actor would, obeying the laws of recognized governments, and I don’t think it’s fair to expect them to do more. If the American people care that much about the free speech of Chinese citizens it’s a matter for our government, not our corporations.