One of the good things about Apple appears to be one of the bad things too. In the old days, the carriers welded the stick and the device makers made what they asked for. Over a year ago, T-Mobile spent $8 Billion as the exclusive winner of the FCC's auction of 600mHZ spectrum.
What put T-Mobile in the game in the first place was their previous $435 Million purchase of 700mHZ. Obviously, the lower the mHZ, the better the signal under ground and indoors. LG and Samsung already have made devices that support this new T-Mobile "Band 71" technology. The problem with Apple is since no other carrier can offer this band, they don't seem very motivated in adding it to their devices just for the benefit if TM customers. To make matters worse, it's not something that can be pushed out as an updated software patch.
I am currently using a Samsung S8+ and an iPhone 6s+. I refuse to buy an iPhone X until it supports Band 71. Until then, I will just plug in my JBL 3.5mm Headset into either of those devices and can wait as long as needed...
Joel Saltzman has over twenty years of wireless industry experience. He is currently CEO and Chief Wireless Analyst for Dr Wireless.