Yup - I eventually figured it out. Mostly because I really enjoyed almost everything in "For You", and it seemed oddly aligned with the musicians I was following, and was a small set, whereas "New" is a vast collection of tracks/playlists/music. New is really poorly named - 99% of the stuff there isn't new at all - some of it from the 70s/80s. I don't know what better name could have been used that wouldn't have been confused with the selection curated specifically for me.
Overall - loving Apple Music, I'm 90% likely to subscribe for $120/year, coming from someone who spends about $20-$30 a year on a few select tracks and the rare album.
Sorry for the late reply, but as far as I can figure "New" isn't about the tracks' newness, it's about you looking for "New" music to assign to "My Music".
"My Music" is for things you own or already access.
"For you" is for new things Apple thinks you might like based on your preferences.
"New" is for completely new things to add to your collection.
