AT&T HTC One M9 and M8 are finally being updated to Android Marshmallow (starting tomorrow)
Now, Mo Versi, Vice President of Product Management at HTC, revealed that the wait is about to end. Starting tomorrow, May 12, Android Marshmallow will be available over the air to the AT&T One M9 and One M8 (though it's possible that not all users will receive the update on the same day). As always, you'll be able to manually check if the update is available by going to Settings -> About -> Software updates on your device.
The One M9 and One M8 are no longer available to buy from AT&T. Weird enough, the only HTC handset that AT&T is currently selling is the One A9, as the brand new HTC 10 flagship isn't included in the carrier's plans.
source: Mo Versi (Twitter)