A similar thing happened to me - I lent a phone to my mother-in-law and created an account for her. She returned the phone once her own phone was fixed.
A few years passed, and a couple of weeks ago my phone broke, so I wanted to use that one until I bought a new one. It turned out that Apple had permanently deactivated the iCloud account on that phone. I could make calls, but I couldn’t install or update any apps, even though I still controlled the email address that was used to create the Apple account. Not that 5S is very useful these days but still.
A few years passed, and a couple of weeks ago my phone broke, so I wanted to use that one until I bought a new one. It turned out that Apple had permanently deactivated the iCloud account on that phone. I could make calls, but I couldn’t install or update any apps, even though I still controlled the email address that was used to create the Apple account. Not that 5S is very useful these days but still.