Try to play Joe Jackson's Heaven And Hell. Searching for it shows artist "Joe Jackson & Friends", with the album cover next to it. When you click on the cover or the artist, it takes you to...
At least it's greyed out and you can know that you have ''lost'' a song in your library. Trust me it could be worse. I had 10 000 songs on google play music and when i was losing songs I had no way to know which song disappeared...
Love how a single mix tracks are greyed out on A State of Trance albums but I also noticed under Armin Van Buuren music profile you can find the Mix tracks so there is both versions sadly they are hidden for us to find. Apple really needs to bring back the old search or give us a option of better searching.
Trust me Spotify also has this problem it is just stupid labels being greedy they act like they don't get enough. Here is a idea for the artist maybe you should make better music to get more attention or troll like Taylor Swift make songs about breaking up or complain to Apple about pay through Twitter.
I had a similar problem after something went wrong with my account due to ending my Apple Music subscription and then starting it again, after which point hardly any of my playlist tunes were accessible (all greyed out).
To fix it I did the following:
Go to Settings > Music.
Switched off iCloud Music Library.
Restarted my iPhone.
Double checked Settings > Music again and for some reason iCloud Music Library was still active, so repeated steps 2 and 3 again.
Finally it was disabled, and opening Apple Music all of my iCloud playlists were gone.
Enabled it again, opened Apple Music and left it for 5 mins to sync my iCloud Music Library again and hey presto all tracks were back and available!