T-Mobile has updated its support website to reflect that
Starting with November 14, T-Mobile customers in the United States will be able to enjoy the features that Google’s new Nexus smartphone packs inside, and it seems that they will also be treated with some extra capabilities.Previously said to arrive on shelves without support for WiFi Calling, the LG Nexus 4 will actually sport the feature when released, it seems.
T-Mobile has updated it support website to reflect the fact that full WiFi calling is supported on the device, as long as users have a GBA SIM card (usually labeled TM9 177) and register their 9-1-1 address at my.t-mobile.com.
If these requirements are met and the smartphone is connected to a WiFi network, users will be able to make calls over this connection, as long as they do not leave the hotspot’s range.
Update: According to T-Mobile, the support info was published in error, and the phone won't sport the feature when released.