Good Dj's are in the position to built a playlist to keep the good vibes grooving.
We don't play music because it's on the radio or on any charts. We play music that feels good and know the one or two songs of an album that didn't make it to the charts but are dope!
While songs like "Say It Right" or "Promiscous" from Nelly Furtado's Loose Album ran the charts, good Dj's know that "Wait For You" is a dope song too and people need to hear it.
While everybody is listening to the awful Tekashi 6ix9ine or all the new "Lil ..." rappers a good DJ knows that Busta Rhymes did a new Song with Mariah Carey and it sounds like "I Know What You Want part2".
So what I'm trying to say, as you already got an algorithm to do some good transitions from one song to another one.
Let good DJ's like me mix some Playlists for the users, with songs that are already able on Spotify, to get the extra potion of good feeling in their car ride, under the shower or maybe while doing some love with their partners.
Let us DJ's do the work for a good transition without any siren or annoying Dj shoutouts. Just the good switch from one song to the other one.