If an average golfer (I realize not everyone would have the same results as Dan and he's not "average") can get an extra ~10 yards with an iron without sacrificing its ability to hold the green (thanks higher launch), doesn't that imply that you get to take one less club though? If Dan gets a 175 yard shot with his BRx, he now can take an 8i instead of a 7i, ceteris paribus, he'll have a better chance to make a more accurate approach shot.
Does it matter which number is on the club as long as it gets near the hole? I think you are right and you provide an example of someone on the opposite end of the spectrum from Dan. But the lesson in the video is the same regardless: get fit to a ball that maximizes your game. For Dan, maximizing means less spin. For someone else, its adding spin/launch. For your example of an average swing golfer, maximizing may mean gaining distance without sacrificing hold on greens.
One thing though: A lower number iron isn't really an indicator of a more accurate approach shot. I prefer the closer you are as a marker that you can be more accurate. For example, from 175 yards Dan may mash a 9i, hit a smooth 8i or 3/4 7i to reach the green. I would guess that given 100 shots, the 8i is actually going to be the most accurate over the 9i as he is swinging more in control.