Back in the middle of the last century - before all the fancy ways the computer tells us how to bat & throw, it was ‘breaking your wrist’ to determine whether it was a checked swing or not OR if your wrist ‘rolled over’ it was a swing.
You are correct though that it does appear to get called even though wrists not rolled but head of bat is ahead of body.....or something like that.. <: <: <:
In 1969 it was not break your wrist. It was the position of the bat and how far it went over the plate.