Here's my update of my goat rope today.
Reserved a 7+ 128 MB on the IUP link with a store 90 minutes from me. Drove there this afternoon for my appointment, and had no issues with being able to purchase on ATT Next even though I'm not in the IUP. BUT....
I didn't get my phone. Here's why. My 6s+, that I own outright had a Best Buy reservation against it.
I was gonna trade in my wife's 6+ for the new 7+ and give her my 6s+ that I owned outright. Since I had made 18 payments to ATT, I could give them the 6+ back, and upgrade.
Long story short, the ATT rep that I called said if you were doing a trade in on the NEXT program, you had to do it in a corporate ATT store. So, I paid off my wife's 6+, and wanted to use hers as planned. Except....the payoff info had not replicated for third party vendors such as an Apple Store. I was told it would take up to 24 hours before the Apple Store folks would be able to see that line released and ready for upgrade.
So, I called Best Buy and cancelled my preorder with them, hoping it would release my 6s+ line immediately. But no go. Looked like it's gonna take a while for that line to release as well.
So, they are holding the 7+ for me until the end of the day tomorrow. I'm gonna drive back after lunch tomorrow, and hope at least one of the lines is released and ready for upgrade on ATT Next. I really didn't think it would take that long for the released lines to proprigate through the system so that the Apple folks could see it.
Hopefully after another road trip tomorrow, I'll be done with this years release.
Note: Since I paid off my wife's 6+, and already owned my 6s+ outright, I was gonna enroll in the Apple IUP. Unfortunately, you have to have a straight credit card for that, and not a Visa debt card. The debit card is all I have, so I have to use ATT Next.
I'll update if all goes well tomorrow. Thanks to everyone providing info on this thread. You guys are awesome!