HTC recently confirmed that most of their devices from 2013 or newer, and the One M8 is on that list. Some people may forget that HTC released back in 2014 a Google Play Edition of the One M8, with pure stock Android onboard. It now looks like HTC wants to update that device by the end of this month.
HTC’s Vice President Mo Versi recently tweeted that HTC wants the One M8 GPE to get Marshmallow by the end of the month. That may not happen, but since it is running stock Android, HTC just needs to include support for features the One M8 exclusively has, such as the Dual rear cameras.
@athreya7777 M8 GPE will include Marshmallow OS update. Our target is this month. Will advise once we are close to release.
— Mo Versi (@moversi) October 6, 2015
There obviously aren’t any promises being made here, but it would be on of the first non-Nexus or non-Android One devices to get Marshmallow. So if you have a HTC One M8 GPE, be on the lookout for a possible update to Android 6.0 soon.