iPhone 5 Purchase Gotcha

I ordered iPhone 5 32gb black AT&T as an upgrade ($299) at 5am ET on pre-order day. By that point, my delivery was already October 5.

On launch day, I went to the Apple Store at Garden State Plaza (Paramus, NJ) where at 11am the line was under 1 hour and there was still ample inventory available.

However, I was informed by Apple rep that cancelling the pre-order was not all that simple. True, I could cancel the pre-order with Apple, but since the upgrade eligibility needed to be validated through AT&T, it would take AT&T's system between 48-72 hours to release the pre-ordered upgrade so that I would not be charged full price for the phone. My choices were either to cancel, wait until Monday or Tuesday for release to clear and take my chances on inventory. Or, just wait another two weeks until I receive the pre-ordered phone. I opted to wait for the pre-order.

Is this valid information from the Apple Store representative?