Does the 90 day iTunes lockout period effect only music?

I have bought a used 12.9 iPad Pro as a Christmas present for my dad. My secret mission was to set it up and hand it over to him with his profile, music and apps all ready to go.

I decided to test the iPad's functionality using my Apple ID to test speakers and screen using music and apps I am familiar with. The plan was to then sign out and wipe the iPad and find a sneaky moment I could put his ID on it and quickly remove the Apple new device messages form his email...

However, when I went to the music app on the iPad I got the 90 day lockout message (with 78 days still to go). This is the first time I've come across this issue and I'm learning it's a bone of contention for a lot of people. Fortunately, as 12 days had already elapsed, my account sign in was not the cause and I don't need to blame myself for this, and at least I am now aware of the problem now rather than on Christmas Day!

I would really like to know what exactly is effected by this lockout? Is this iTunes specific i.e. music, movies, etc.? Or does it also include apps from the app store? For example, my dad recently paid for a Times newspaper app subscription on his current iPad - will he no longer be able to access what he has paid for on the new device? Can you just go to the app store and hit purchase again but receive the apps free if they've already been paid for?

I bought this iPad from a store and I can still return it but I might have the same problem again with the next one...

Any advice/help would be appreciated.