Did not pre-order. Used Apple's Reservation system, which meant I had to upgrade with the iPhone Upgrade program. Ideally, e-mail also stated that I could switch up my payment to carrier upgrade or pay-in-full in store when I went to claim my reservation. Did carrier upgrade. Got my 256gb iPhone 7 Plus without even pre-ordering. I was inspired by my friend who pre-ordered with AT&T and they did not even send out any tracking/shipping updates and gave him an estimate of early October. He got the phone on 9/18 in-store. I got mine 9/20
Unfortunately, Apple has become stricter in terms of the policy with the reservations, as they now allow you to check out however you wish but you have to be an actual existing member of the Apple iPhone upgrade program. Guess I got lucky.