I have been reading the review guideline: https://developer.apple.com/app-store/review/guidelines/
I see section about for subscription its has to be available for all iOS devices of a single user:
Content subscriptions using IAP must last a minimum of 7 days and be available to the user from all of their iOS devices.
But does that apply to Non-Consumable Content as well?
I am worry Apple will reject our app because of this reason.
Best Answer
You are afraid Apple will reject your app because you use non-consumable content on only one device?
One of my project has in-app purchases only for 1 device. The app is already 6 years continuously reviewed and successfully deployed. Believe me, this is not an issue aslong you are not using a subscription.
The only problem you are facing is someone can buy the DLC also on a other device and it will auto unlock as it has already been purchased with the same Apple ID. There are ways to prevent this by securing your app via a database.