That was recently confirmed by a Huawei spokesperson recently quoted saying:
“I can confirm that Huawei will be releasing the third Google phone on T-Mobile this year”.
We spotted the phone earlier this year at Mobile World Congress, but at the time, it was turned off and besides for its existence and the fact that it was running Android, there was little information about it. Furthermore, the design that was shown at MWC won’t be identical to what T-Mobile is going to get. Note that Huawei call this phone the “third” Android device from T-Mobile, and while the second has not been announced, HTC is one more time at the top of the list of candidates.