well if KOF96 was originally released by JY, it might have been in 1997, and NT only released their version in 1998. I guess we won't know for sure unless someone finds the JY version.
and okay maybe Harry's Legend was made by Cheng. but I *really* don't think Cheng programmed ABAB's original games - Panda Adventure for example seems more like the sort of simple game a new programmer or even a student would make, rather than the guy who programmed Titenic and stuff.
as for The Legend, maybe it wasnt made by ABAB's programmer at all - someone must have kept SFIV's source for 11 years, so it could have been updated anytime between 1994 and 2005, and just never released (or released in small quantities).