I'm a first time customer for Apple...always had androids and I've never had this problem until now. I don't see why it should make a difference lol...if they're going to work that way they should only have orders available through their website alone. Really bad experience off the bat for someone coming to iOS from androids.
It's mostly ATTs ineptitude. Seriously they have no idea how to manage and fulfill orders at this volume. from previous experience with them, I wouldn't doubt that's Apple is asking ATT what they need, and ATT having no clue what or how to give Apple accurate numbers to fulfill their orders.
Unless miracle, start checking Apple's reservation system every morning.
Like I detailed before. I preordered an iPhone 5 through ATT a few minutes after it became available and ended up driving to the ATT store 2 weeks after launch to pickup the exact same model from store stock while my order was still on processing. I had even called to make sure all was ok with my preorder. That should tell you all you need to know.