Thanks he will try that later. He is still hoping to recover his playlists but it sounds like he better just try and save his music on his laptop.
If his “laptop” is a MacBook his music/playlists should sync back to his iPhone automatically...the same if he has a Windows laptop and has the “iTunes for Windows” program installed (”re-sync playlists”). Does he make iPhone back-ups to the iCloud or his PC? He could always restore from a prior back-up before the update...(although I have never heard of an iPhone update messing with music playlists for purchased/owned music files). Sounds like it may be an Apple Music subscription issue? Good luck, might be best to call Apple support with details.
https://getsupport.apple.com/solutions