Earlier quoted context omitted.
Have school grades ever deflated? Or undergone some sort of correction? No citation needed, anecdotes are fine.
Yes. At my school we had a real curve. If we all got perfect scores, that's a C for everyone. (More often we all got 15s and they became C's). Teachers who gave too many A's would be benched. We laughed at Ivy League 4.0s which just require a phone call from a parent.
My wife went there, and while most STEM grad schools understood that grades at MIT were not inflated, medical schools did not seem to care. One of her friends had to first get inflated grades doing a STEM masters degree before she could get into med school due to her uninflated MIT undergrad grades.