I don't think he is being contrarian just for the sake of it. He is just using the platform to raise awareness about issues which are serious but don't make the same impact into public discussions and don't get similar levels of support. There is nothing bad in bringing more issues to light, and now seems the perfect time for this when the public appetite is ready for such issues.
I see your point but isn't easy to understand that the reason tech companies and YC try to help the ACLU is because charity begins at home? Preventing engineers from working at these companies because of their national origin affects them more than police violence against black people. There surely are other causes more worthy of support outside the US that he did not mention.
