My theory is that mostly 6+ people got the text messages. I ordered about 10 CDT on Monday and have seen little movement on my order until I got a text and email tonight.
I do suspect the 64G versions phone is going to turn out to be the most popular next to the 16G versions. The $99 down payment and EIP is a sweet deal. So I think that is where there might be a short fall if any for the sat/sun orders.
My guess is everyone who ordered 6/16g from Friday to Sunday gets the phone on Friday. All 6/64G/128G and 6+/64G/128G will be shipped but there is likely be a short fall especially for non-Jump customers. I'd also bet everyone who ordered Friday between 12:01am and noon will get a phone but after that it's just what is remaining in stock.
If you got a text, email, had a CC charged, or have a UPS label in the last 48 hours I think you are good. My predictions include new customers as we'll and jump and non jump customers.
Everyone else I think it is going to hit/miss as stock is monitored and allocated. I do think that T-Mobile is trying to ship as best as possible. Keep in mind this is the biggest launch ever and no one expected it. Best they could measure against was the previous preorder weekend which was only 1 million phones. This time it was 4 million and no one, not even Apple seems to expect 4 million preorders even account for people orders 2 or whatever that they did to make sure they got a phone. Those same people do that anyway so that's not a factor in the over all load.