Тестирование покупки в приложении перед запуском

So here is the scenario:

1. You have already tested your in-app purchase code in the sandbox environment and everything went perfectly.
2. Your app is now "Ready for Sale" and you want to make sure in-app purchases work flawlessly prior to actually letting your app hit the app store.

To try this, I downloaded a "pre-release" version from the App Store using a promo code, but when I try to purchase the unlocked version, it no longer finds the product like it did in the sandbox environment and my "transaction error" alert view will pop up saying the in-app purchase failed.

My question is this: Is the in-app purchase unavailable prior to the app going live on the App Store (in my scenario where I downloaded it early via a promo code)? For instance, when I set my availability date for Friday and the app is finally in the wild, will the in-app purchase show up and allow users to purchase it, assuming it worked in the sandbox?

Thanks for any insights! Greatly appreciated.