Looks like all your waiting is finally over Nexus 6 owners on T-Mobile. The highly desired Android 5.1 Lollipop update is underway for your device. It only took a few days to launch after the other Nexus line started picking it up. The build number attached is LMY47M and will only go out over Wi-Fi at the moment. They state a cell update will commence at a later date. I assume this is to get all the Nexus 6 owners to steer clear of clogging the network for the update. Which is sad for many since Wi-Fi is generally slower than T-Mobile’s own 4G LTE network.
The device page at T-Mobile support only lists Device Anti-Theft in the new feature section along with software stability and various bug fixes. We know Android 5.1 also brings along HD voice to the device as well. At least, that is what Google said.
You all know what to do. Charge up your N6 over 50%, hit a solid Wi-Fi connection and check for updates. Enjoy.
Source: T-Mobile Via Droid-Life