I use the web version and when clicking an artist's name I only see a description for well-known ones. Other channels don't show any description even though the YouTube side has one.
I assume one requirement for getting genAI tracks is being initially fine with hearing music from random channels and also hearing music produced after 2022; if one only cares (for example) about pre-2020 very well-known music they're probably going to be safe.
I regularly listen to recent music, but often tracks I explicitly search for, and autoplay based on those I “liked”. My “Liked Music” playlist has several thousand entries, so I suspect that heavily steers what I’m presented with.