One T-Mobile Galaxy Note 5 user has apparently received the Android Marshmallow v6.0 update. The name of the user is Danon Brown, a senior member at XDA-Developers.
Brown talked about the whole incident on the XDA-Developers via a thread. As per him, he was playing around with his phone and ran into some issues related to the IMEI number. In order to restore the phone to its stock firmware, he used Samsung’s Odin software. When he was done with restoration, he checked for updates to jump to the latest firmware version for the Galaxy Note 5. But incidentally, the device received an update to with build number MRA58K.N920TUVU2DOK5. For those who are unaware, the MRA58K represents the firmware for Android Marshmallow v6.0.
He also posted a lot of screenshots on his XDA thread in order to back up his claim of receiving the update. In the screenshots, you can easily see the visual changes like in the icons, but there are many on the thread who claimed it to be a theme. However, he also posted a screenshot showing that the phone has only one theme which is the default theme. He also showed a few screenshots in which one can see the Hangouts and Gmail apps asking for allowing the app permission during the first-time run. However, Brown said that he was not able to resolve the IMEI number issue even after the update.
It is not really clear whether Brown has really received the Marshmallow update or he is just fooling around with others. Even though if his claim is genuine, one thing is for sure that it will not be the final build. Samsung is currently working on the Android Marshmallow update and it is official roll out is surely months away. In meanwhile, you can look at the screenshots posted by Brown below: