Guys don't worry, if you got a 9/16 delivery date you're fine. Just checked my FedEx tracking and shows the ship date from FedEx is 9/15 with overnight delivery. When the emails come out they'll come out in droves. I asked a friend when he got his email for an iPhone 13 mini from Xfinity last year with launch day delivery, he checked and it was Thursday 9/23/21.
The delivery date you have is the day you'll get it. I have never seen it get delayed when you have that date. Sometimes a later date will get bumped up to launch, but not the other way around. I can't say 100% obviously, but don't drive yourself crazy. I'm confident you'll have your iPhone Friday. Glad I asked my friend to check his email date. My email for 13 Pro Max was 9/21/21 for launch day delivery on 9/24/22.
So relax!