So what did this game mean? Should I change my views based on this one game?
1) Obviously, we want to avoid putting too much weight on one game, so let's get that out of the way, but "We'll it was just one game, so I can't draw any conclusion at all." is just as lazy and erroneous a take as "Based on what I saw, we are Super Bowl bound and Mac is TB12 reborn." So,
2) Mac played a good game, a really good game, arguably. His stats are sound - it's particularly gratifying to see zero turnovers, which was a point of emphasis for him - and in the "critical moments," he really did come through, in contradiction of his critics' view that he is incapable of rising to such occasions. People who claim the performance means nothing and those who damn it with faint praise are full of it, likely more interested in defending their pre-game evaluations than in actually learning from the game and Mac's performance. He had a good game in a fashion of his detractors have deemed him incapable. That's meaningful. Does it mean he is for sure a "franchise quarterback"? Nope, not yet, at all. Does it mean they should now sign him to a long-term deal enshrining him as our can't-fail qb for the next 20 years? Nope. But he had a good game, which certainly suggest he has more potential than the haters have said. Add to what we saw Sunday that he has had the most ill-managed opportunity to show what he can do I can remember any rookie qb ever having, that he has been the victim of gross incompetence on the part of his GM, arguable of his HC, and there is a legitimate basis for optimism.
3) My take on the whole Belichick issue is unaffected by this game. Bill has been, over the past several years, a fireably incompetent GM. He must be deprived of this position's responsibilities immediately, entirely, and in perpetuity. If that means we lose his services also as HC, I don't much care. I am firmly of the opinion that he has shown significant decline in that area of his responsibilities as well, not only re Mac, but with respect to in-game decisions, inconsistency in the quality of game-planning, unaccountably weird and self-defeating personnel decisions, etc.
4) I have been open to the possibility that we might keep Mac another year both to give him a more full and fair evaluation, and to have him around possibly as a transitional qb should we draft a qb who needs time to develop. Yesterdays game only makes me more comfortably with this view.
All in all, yesterday;s game was genuinely, solidly encouraging, particularly with respect to Mac, whatever the I'm-such-a-hardo naysaying poseurs may assert.