I went back and watched the video of the shot and result twice more.
I also looked at the official pin sheet for the day. The pin was 30 yards from the front, and 4 yards from the left edge.
Based on these pieces of information, it appears to me that the ball first bounced about 18 yards short of the hole.
In the cited Golf Digest article, Schauffele says the wind appeared to be "down cut", so he thinks the ball will drift right a bit. And down breezes can be tricky, as they sometimes knock a shot down.
Let's imagine they were talking about the shot for a long time because the distance was awkward, hard to choose between a 7- or 8-iron. He feels he needs to make a 2. They expect the 8-iron will come up 6-10 yards short, but the ball tends to bounce forward on that part of the green. If the 7-iron goes too far, then you end up with a 15-30 foot putt down to the hole. In my opinion, very few players make birdie from long/above the hole, while it is much easier to make the putt from short/below the hole. I think it's much harder to read the break from long.
So they decide that he should hit 8, and instead of the ball landing 6-10 yards short, it lands 18 yards short because of shifting winds. That seems plausible.
Once again, I was concerned with the shot immediately, mostly because the divot looked a touch deep. But it was an unusual overhead view of the shot, so maybe it threw me. However, if he did take a little more turf, then he would have struck the ball a bit high on the club face, which might have affected both the spin and the power of the strike. Maybe.
That's my detailed second look at the shot. As a result, I am less confident the result was caused by mishitting the shot.