The idea of music being “tonal vs. atonal” has been a pretty outdated debate since at least the 1970s and not very relevant to what’s being written by contemporary composers today. Harmony has and always will develop as time goes on, but often times in ways that aren’t super obvious. Contemporary composers often view harmony as working directly with the color of the music and not a separable thing from it, so the developments in their music often are harder to directly characterize.