So an update and word of warning for some of you: make sure your trade in has been processed! Yesterday I got a text message from tmo so I called and it turns out when I ordered the rep didn't actually go through the trade in process. If I hadn't known this I may have had to pay for the new 7's I ordered and not been able to trade in my old 6's.
If it was done properly, your account on MyTmo should should both your order for the new phone and also a separate section with your trade in along with a pre-paid label link. When I ordered the rep told me about this but didn't actually complete the trade in part.
Anyhow, my credit has been charged for 1 of my 2 7+'s, I think it's the black 128 gb I'm getting. Haven't been charged for teh gold 128 even though I ordered them at the same time.