Do we know which airlines were flying out of HI at this time. I think the individual airline is the place to look for this info.
For example, on American Airlines (the company) infants can travel with a parent from the second day after delivery, although the airline recommends waiting until at least seven days after delivery.
I don’t have the link now but there was a radio interview with WND. He claims there was a law or a policy that was changed in the 70s. Before this change..the newborn had to be 6 weeks. He was talking like this would be for all airlines.