This is true.... but...
If you follow this thread, other threads and iStockNow... you will see that the Apple store gets regular shipments of iPhones for the other carriers and not so many for T-Mobile. Also... if you have JOD, you have to buy through T-Mobile... so your options are limited. The Apple Online Store doesn't allow you to buy T-Mobile iPhones on any sort of payment plans. Basically.... T-Mobile simply doesn't have the relationship with Apple like AT&T and Verizon do. To make matters worse... if you order from T-Mobile, you get weeks of silence with no updates about the status of the order. I literally didn't here from T-Mobile about my tracking until AFTER I received my device.
T-Mobile is just never going to win in this instance. I would never imagine that T-Mobile would have the same relationship with Apple that At&T and Verizon do. They are the titans of the industry, there's no getting around that. Yes, it sucks, but this is business. Apple is going to cater to them over everyone else.
T-Mobile's computer system sucks. No ifs ands or buts about it. But, as a software developer, i come across companies larger than T-Mobile whose systems are even worse (i.e., some large banks). T-Mobile's notification system could be much better, and compared to its last 2 iPhone launches, it has improved. But, in this particular situation, there is only so much that they can do. For me, once UPS showed an origin scan for my phone was when I started getting the texts/emails from T-Mobile regarding the tracking, payment and returning my device. So, I'm not sure why you didn't hear anything until you received your phone.
Regarding T-Mobile and the "update silence," would you like T-Mobile to consistently send texts basically saying "we don't have any phones and don't know when we'll get any. your shipping date range is still the same"? Because, essentially they've done that with the 11/01 - 11/30 group, and some of those people have come here complaining about those texts.
Simply put, T-Mobile just can't win.