The -3 had some -8-wing that had just been brutally chopped off. Not very efficient. At that time the 787 was overly expensive to build and needed some serious redesign. So they restreamed early built -8s with not enough range to the -3 role and didn't built the -3.
The 787 is still said to be costly to produce but with some custom made short range wing it might nicely fill that niche. And it might fill empty slots in final assembly.