IMO the main flaw is that he couldn’t look at recs, essays, ECs, and other factors that often tip the scales at these schools.
You are maybe confusing Espenshade with the Princeton/DOE case. Princeton shared the data with the DOE but would not publicly release it.
It was NCES data actually. And the data was very limited and is now very old.Some conclusions clearly reflect that, like that back then more men than women applied to selective colleges -that has reversed.
That kind of glaring weakness (for making broad claims about college admissions today) aside, Maybe read the actual study. There is fascinating stuff in there, it’s a good read.
But as far as I can discern, scores and race and athletic/legacy were all they had for all 3 colleges all 3 years. At only one college did they even have GPA and class rank for the 3 years.