It was actually the other way around. It would play me songs technically within the same broad genre (Hip Hop, RnB, Pop) but wildly different sound.
It felt less like a music genome project and more like this typical nonsense streaming platforms do, "people who listen to song A, also tend to listen to song B".
(two songs in widly distant genres/production styles can still be very similar on rythm, tonality, chords, tension, progression, structure, etc.)