So I just got off the phone with ATT (after a long hold!). I pre-ordered over the phone around 8:45 am est on the 14th. I initially received an email that said my order would ship on 9/21.
Last night I received an email saying my order would ship in 14-21 business days and was calling ATT to cancel the pre-order this morning (to wait in line on the 21st instead). They told me the email was sent to everyone who pre-ordered and assured me that my order would ship 9/20 for a 9/21 delivery, and that anyone who ordered by 11:30 would be receiving their orders on 9/21.
Also, my order was shown as backordered on the check status page up until last night.
I didn't get an email like you got that says your order will ship in 14-21 days. Mine says I will get it on the 21st and I already got charged for the phone. So I don't know what the Rep you talked to is talking about. I ordered about 5 min after the phone went on sale on AT&T website