Tmobile Band 71/600mhz

I was checking the specs for both the iPhone 8/8 Plus and X, and it appears that they are not in par with Tmobile's 600mhz. Is that right? If so then it's a pretty expensive device to own if LTE technology is behind. I don't know if this is somehow intentional on Apples' part to sell next years "S" series like what they did the iPhone 3G which then they came out with 3GS.