We're not doing the suncrusher and Kyp Durron just for a mini campaign. The Sun Crusher would be far too overpowered, and it wouldn't make sense if it just disappeared after this. Kyp durron was also way too young to use as a hero. The New Republic already have Luke, Corran Horn, Mara, Cilghal and Kam Solusar for jedi, all of whom were there before Kyp (except maybe Mara) so he wouldn't be your first jedi hero. And besides that, Kyp wasn't actually working for the New Republic during that time, he was doing whatever he wanted.
What we're trying to do here is get some small events that would fit within the context of a GC with a clear bonus that makes it worth doing for the player, not make a full story campaign with several missions per event inside a GC.