The Motorola Moto X (2nd gen) was strangely not included in the list of Motorola phones that will be receiving the Android 6.0 Marshmallow update. Motorola only lists the Moto X Pure Edition (2nd gen) to get the update and not the carrier variant Moto X.
It’s possible they just forgot to include it or made a mistake, but according to Matt, the Motorola forums manager, the AT&T and Verizon variants definitely will not be updated to the latest version of Android.
That really sucks for the Moto X owners because the phone is only about one year old. Technically, this isn’t officially from the high ups at Motorola and they might update it in the future, but it isn’t looking good.