I am confused. I'd like to understand why anybody actually needed to order through the AT&T site versus ordering direct from Apple.
This year I ordered from AT&T because it was online first. In all other years I have ordered direct from Apple. I have never lost my grandfathered unlimited data plan.
The only reason that might make sense is if the next plan requires that you get your phone directly from AT&T?
No. If you have an old plan and you want subsidy, you must order via ATT and ATT only.