A convincing argument, well put. I think for the most part I agree with you.. Where I differ from you is that I feel that he's conservative by nature and has used analytics to increase aggression.
One other random conjecture...
I think McVay's conservative nature in part stems from a healthy confidence (which borders on arrogance). I imagine McVay might think, "no one is better prepared than we are, no one can execute better when we are on our game. So if we keep following the analytics, we will consistently improve our chances of winning. Keep making the choice that is 70% likely to succeed. Don't be over-aggressive and take unnecessary risks."
Also... I want to give McVay credit for occasionally being plugged-in to the emotional flow of the game. I don't want to portray him as some over-analytical cerebral robot. There was a GREAT shot of McVay giving the entire offense a motivational talk in the 4th quarter of the Eagles game. I don't think it's a coincidence that that pep talk led to 14 points and a victory.