As I just had to find out from Spotify support, they removed playlist notifications from Spotify.
The notifications are being disabled and soon they will disappear for all users. You can still get notifications via e-mail though. You can set that up here
If you'd like the notifications back, feel free to post on the Spotify Community.
At the moment new songs added to playlists you follow will no longer be denoted.
We've made the change as of December. It's not a technical issue, we'd mainly like to avoid "spamming" our users.
As of last year also the blue dot indicator (next to the playlists) was removed, there is now way anymore to tell if new songs got added to a playlist - besides email notifications.
But I don’t want email notifications. I want these notifications within the app itself.
At least make it configurable which notifications you want to see when clicking on the notification button.
What's the next thing they're going to remove?
Who also wants playlist notifications back?
Updated on 2022-06-08
Thanks for bringing us your feedback in the Spotify Idea Exchange.
We see this still seems to be talked about on the Community, so we're reopening votes for the idea. We'll continue to monitor and check out the comments here, too.
As soon as we have any updates on its status, we'll let you know.
More info on how your feedback reaches Spotify via the Idea Exchange can be found here.