Wow, that’s a terrible idea. I do love the idea of the Imperial Remnant and New Republic teaming up against an external threat. There’s no doubt in my mind that that threat should be he Yuuzhan Vong, and I say that as someone who’s never read any of the books they’re in. The idea of these super metal looking baddies wielding biotechnology just sounds awesome, and suitably alien for a race from another galaxy.
Reimagine the Yuuzhan Vong into Gigeresque biomechanical monstronsities, and the Yuuzhan Vong gods into Lovecraftian entities, and I’d get behind that.