HTC One (M8) for Windows (GSM)
T-Mobile Band 2 LTE
Will there be an update so that the Android version supports band 2 LTE?
The M8 supports Band 2, although it may be disabled in a carrier-specific version.
So that means the M8 went through the FCC testing with band 2 LTE. Which must mean that T-Mobile could push out an update to enable that on all phones without resubmitting the phone to the FCC?
Looking at the HTC spec sheet, the T-Mobile version is limited to 700/AWS. The AT&T version supports 1900.
This was confirmed my numerous posts in XDA Developers.
If you don't already have the phone, get an AT&T version and get it unlocked. That will give you the bands supported by both AT&T and T-Mobile (including Band 2). If you bought the T-Mobile version, you're SOL.