I would love a book on Neelix -- relaunch or not. Maybe his history before on Voyager. I dont care.
Neelix's backstory is told, along with those of most of the other VGR regulars, in Jeri Taylor's novel Pathways
How about his life post VOY returning to San Fran? He has been maybe mentioned twice in Golden's relaunch. Maybe a short story on his life with his new family and an update on whats going on in the Delta Quandrant. Maybe he can report on the Hirogen, or Kazon, or Ocampa, or whatever.
Final idea is to ignore Neelix all together, create a whole new Talaxian, and work him/her into a new story based during the whole war that was mentioned. There was an episode where a Dr was onboard VOY and tried to get a family member back. I always liked that story line and wanted to learn more. Since there is little established with it, you could probably be quite creative.