Yep, it'll come sometime this week. Tmobile receive shipments from Apple every day including weekends (I'm excluding Sundays just to be safe) and I don't think from at least what I've heard that Tmobile has control over what exact phones they receive, they just receive whatever Apple gives them. Granted, they get a lot of phones but it's just a case of waiting until they get enough of the 6+ 16GB Gold to fulfill other people's orders.
I too am waiting for a 6+ 16GB Gold, my SG 64GB 6+ has already shipped and will be here before noon tomorrow.

I gave up hope but it looks like everything went through fine.
Also, I received the T-Mobile "you're being charged now" email a full day after shipment. Don't look at your credit card for any help because it won't always be in time.
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You will not be waiting 6 weeks, I promise. T-Mobile are legally required to mention the worst case because they don't want to be sued and what not.
Again, same advice for everyone: Wait until Tuesday morning and then call them up, email John and whatever. PM me on Tuesday morning for the number if you'd like. Giving them a full business day is only fair. Honestly, I really do believe you'll see movement sometime Monday or even Monday night/early Tuesday. Just give it until then and if there's nothing you'll have a strong, strong case to present to CS when you phone them up for compensation.