Right now, the Android Version 6.0 (also known as Marshmallow or Android M) is happening on a lot of well-known Android devices, such as those on HTC, Sony, Samsung, Motorola, and LG. As far as the newer LG devices getting the Android Marshmallow upgrade, it looks like this is happening. This is the latest news on the Android M Version 6.0 Marshmallow Release Date for LG G5, G4, G3, G2, G Stylo, and V10 on Sprint, US Cellular, T-Mobile, Verizon, and AT&T.
It goes without saying that the latest flagship phone from LG, the G5, has Android 6.0 right out of the box. It would appear that last year's flagship phone, the LG G4 has received it on all carriers including US Cellular, T-Mobile, AT&T, Verizon, with Sprint being the first to receive it as early as last December.
So, working down, the next Android device to receive the Android Marshmallow upgrade is the LG G3, the flagship phone from two years ago. A recent report from Neurogadget matches what was reported here a week ago, in that only Verizon has upgraded the G3. The other carriers have not announced yet when they will rollout Marshmallow to this model.
The V10 is also an Android device from LG that is planning to receive Android M to all of its carriers, but again, only Verizon has it now. There was a tweet from T-Mobile Product Manager Des Smith that the carrier will be giving out their upgrade as an Over The Air (OTA) very soon, and this is about two weeks old.
This is the same situation for the LG G4 Stylo, as well as the LG G Flex 2, but there is no official word yet, according to Tech Radar. It is quite possible that your LG device already has Android 6.0 ready to download for an Over The Air (OTA) update. Therefore, users are encouraged to check your "Settings" and "System Updates" to see if Marshmallow is ready to download. The upgrade might not be ready depending on your U.S. carrier, as it has been shown that Verizon and T-Mobile have Marshmallow available, but some of the other carriers like US Cellular, Sprint, and AT&T do not.
There are some that are saying that the LG G2 could even receive the Android upgrade to Marshmallow, but this does not seem very likely, as the phone is over three years old. Generally, Android phones that are about two years old are the cutting point for not receiving the Android upgrade, but exceptions can be made.