Re: Critical question
Well, I don't know if they've anounced anything about this phone in particular, but on the PRIV, there have been regular updates. Security updates every month (most of the time in the first week of the month, even). I've had my PRIV since December, it had Android 5 out of the box, immediately upgradeable to Android 6. 7 is rumored to be coming this summer.
If that is how they treat this phone as well, you should be covered quite neatly, I'd say.