So I was trying to think about the logistics on how all these pre-orders are handled at AT&T.
When you go to a store and buy a new phone it takes them literally 10 -20 minutes to pull up your account, scan your phone, scan new sim card, put in the sim, and activate the phone.
Now remove the activation and add in the time to package and print a shipping label. Even if they streamline the process it takes some time.
Now apple probably gives them an estimate of how many phones they will be receiving, but until the plane is packed, unpacked, and delivered AT&T probably doesnt know how many they are going to get.
Then to take the time to match up each phone to an account prior to allocating each phone to an account would add a massive amount of time to the processes.
So I think they have an idea of how many phones their getting which they use to generate the shipping estimates. Now after that, till the computer supplies your account to personal (based on order the preorder was processed) who is adding the phone and sim to your account, puts the sim in the phone, and packaging the box they have no idea who getting a phone or not.
Any other way would just add a massive amount of time to the process. This has to be done for hundreds of thousands of phones, it takes time.
Now apple does this to create buzz, they could have announced it on the 12th with a release date of say October 10th and preorders on the October3rd. This would have given them almost a month to get the phones to the US, into the carriers warehouses and inventory. Then as the pre-orders happened they could immediately tie IEMI numbers to each order. This would allow them to know exactly who was or was not getting them on launch day.