Waited about 59 minutes on hold but finally got a representative at Best Buy. They are telling me that the $100 Gift Card came directly from Corporate. This bypasses the system in place by Best Buy. The nice thing about this is that Best Buy was trying to deliver the bad news to customers before the 16th and as quickly as possible.
The bad news is the information is not correctly populating on the orders in Best Buy's system. So while it all looks rosy and that you will still receive your phone tomorrow, according to Customer Service, this is not true in 99.9999% of the cases. The rep specifically said that Corporate did not reach out the call centers or BestBuy.com team and let them know what was going on. They learned from customers calling in, who received the $100 email, and from Macrumors.
While I am not telling anyone what to do, I canceled my order. If you are using a program like AT&T Next, the Rep has to get in touch with the "back office team" to free up the line to make it upgrade eligible again. Otherwise, you can't go get a phone somewhere else without a ton of issues. This process took an additional 3 to 5 minutes but now my line is supposedly ready to upgrade again, via AT&T Next, within an hour.
Good luck to everyone. Hope you get the phone you want in as timely of a manner as possible!