It is rather difficult to compare students 30-40 years apart:
First, SAT scores are now inflated. For example, the average SAT math score went up from 497 in 1984 to 513 in 2014. When they revised the SAT in 2017, it jumped up to 527. It is meaningless to compare scores that far back in time with today.
High school GPA’s are inflated. First, there is general inflation—no one likes to give C’s or below these days. Also Honors and AP grades are scaled. It is now possible to get over a 4.0 because for example at some schools an AP course A is worth a 4.5 and an honors A is worth a 4.2. Back in the 80’s, this was not common.
ND has always accepted athletes with grades/test scores below the average for the university overall. I think this is universal and falls in the exceptional ability category.
What I sense is different about Kelly is that they are now targeting HS sophomores and juniors, getting them engaged with admissions earlier in their process to ensure they are taking the appropriate classes to make it into ND. This in essence widens the pool of those available to ND given the student has enough interest for n their education to prepare.
My sense is there is not a big difference in the GPA/test scores of the student athletes ND signs versus other schools. What is different is they expect just a few more specific classes (e.g. foreign language), Also, they must make real progress towards a degree once enrolled.