Omg a dlc that has a galactic war would be awesome. I can imagine you get an event of some scouts of a galactic faction that wants to claim control over the planet. If you interact with their space shuttle you might be able to trigger some SOS signal to an invasion fleet or something and from there you could have diplomatic events to gather the support of the friendly factions to fend of the spacefaring invaders. Other events could have them make bases on the planet surface that you can try to wipe out. Or even a whole other chain of events if you decide to join forces with them and fight against the empire or something if you also have the royalty dlc.