The real wisdom to take away from this is that you need to keep copies of everything you've ever entrusted to iCloud because iCloud cannot be trusted. This was one instance where a giftcard seems to have caused someone to lose access to their stuff, but there's nothing stopping some other random thing fully outside of your control from causing Apple to kick you out of the things you've given them to keep for you.

Everything in the cloud is at risk of being taken from you. Companies like Apple are not your friend. They explicitly make no promises and insist that they are not accountable/liable. Stop trusting them.

Honestly you'll be safer if you don't use any major cloud provider for anything valuable. They've proven over and over again that they are very unreliable.