Re: Marshmallow?
While past performance is no guarantee of future results, with Lollipop the Moto X had a soak test and an update in November 2014, and it too until June for the Turbo to get Lollipop. I think that there were good reasons for a delay, but what Motorola does with one phone doesn't guarantee what they will do with another.
I honestly wonder if Verizon will want to push an update for Advanced Calling 2.0 (wifi calling) on Lollipop for the T2 before they go with Marshmallow, just like they did last year with the Turbo and Advanced Calling 1.0 on KitKat, but I suppose we'll see.
TL;DR: none of us know at all when the update will come. Your guess is as good as mine or anybody else's.