Grey
Dialectical Hermeticist
Yes, it's not a well-documented transition - none of the papers I've read really agreed on when or why we arrived at the second, less formal definitions. I've always thought it was a semi-accidental attempt to distinguish logically derived morals (now ethics) from socially derived morals, probably influenced by pop-culture discourse circa the 1990s.
If I still had university library access I'd look for specifics and clarify for you, but alas I do not.
If I still had university library access I'd look for specifics and clarify for you, but alas I do not.