Based on the new leaked document, the Galaxy Note 5 and the Galaxy S6 Edge+ will be the first to receive the Marshmallow treatment in the first few days of February. Then between February and March, the OS updates will roll out to the Galaxy S6 Edge and the Galaxy S6. Then from March to April, the Marshmallow updates shall come to the Galaxy Note 4, the Galaxy S5, and the Galaxy Note Edge.
Subsequently, the Android 6.0 Marshmallow updates will come to other Samsung devices including the Galaxy Tab S2 9.7, Galaxy Tab S2 8, Galaxy Tab S8.4, Galaxy Tab A9.7 and Galaxy Tab A8 tablets, Galaxy Alpha, Galaxy A3, A5, Galaxy E5 and E7, Galaxy J2, J5, and J7.
Samsung has yet to roll out a Galaxy S5 Android 6.0 Marshmallow beta but the update is already confirmed. UK-based telecom carrier, T-Mobile, confirmed early this year the Galaxy S5 Marshmallow release but it said that the update is currently in the manufacturer development phase.
What T-Mobile meant by it is that the update has yet to go through them or other telecom carriers for that matter before testing is done prior to its eventual public release.
The fact that T-Mobile is planning to release an Android 6.0 Marshmallow update for Samsung Galaxy S5 is a good sign for other Galaxy S5 users in the US and around the world.