Two publishers, looking for books dealing with diverse characters and subjects, have sprung up. One is Versify, an imprint of Houghton-MifflinHarcourt, and now possibly the only one of that group to accept unagented submissions. Kwame Alexander, The Crossover and other poetic and fabulous books, is the founder. First books come out in 2019.
Kokila is the second imprint I just learned about that focuses on books for diverse audiences that will also read unagented material. Ramata Tripathi is involved here, and I had an excellent and very thoughtful critique from her several years ago at the LA SCBWI conference. Writers and book lovers, check them out.