No it's not: instead it's the prescriptive advice that high school graduates should go to college. But if you follow up one of the references:
"However, when we look at wages for the 25th percentile of college graduates, the picture is not quite so rosy. In fact, there is almost no difference in the wages for this percentile ranking of college graduates and the median wage for high school graduates throughout the entire period. This means that the wages for a sizable share of college graduates below the 25th percentile are actually less than the wages earned by a typical worker with a high school diploma."
https://libertystreeteconomics.newyorkfed.org/2014/09/colleg...