Yep, definitely in the mid to late-80's was when the term started to gain momentum, but as with most things, it was a bit later before the "powers that be" (i.e. Overstreet) finally got off their Ivory Throne and formally
anointed it as such. I don't remember any "post-SA" term being used and it was either "70's Books" (or the all-encompassing Modern Age" for all 70's-on books) and then later, ...