It's virtually free to give him two more shots. To stink it up badly enough with a totally different coaching staff, it will have to be bad enough to pull him and move on. Then it's just pro forma whether he's on the roster or not, if he's that bad.
I don't see that happening. I see him being goodish. Competent. What it said on the tin before last year's regression.
I do worry with him that we assume a mature QB who rolls with things not going his way, but he might not be that guy. He might carry last year with him always, and not in a "revenge fuel," TFB-injured-again-with-shoulder-chip way. Hopefully not, but it's always possible that we broke Mac (if so, he was pretty breakable).
I'd love to see success for him. I'd love to be a fly on his cranium wall to see what he's thinking as J. Meyers gets hired in LV. Oh, the story lines, right?