[quote=WilsonTurner]
The Supremes would still be flying, and would probably more advanced than ever. Perhaps they, after the many thousands of years, have found their culture diminished, and offered to bring the former space-ruling species back to spaceworthiness, in return for cultural enlightenment. Then the Supremes would have positive relations with most, and everyone would have a legitimate reason to be in space, and it'd make a nice backstory as well. Supremes welcoming old friends into ship previously unexplored would be good for character development and the like.
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Im going to say no.
The point of the sequel is that the new civs have to discover what happened by finding remnants of the old civs and defeat what destroyed the old civs. If the supremes survive it breaks the point. That and this sequel would occur 1000s of years after the current RP so all civs would have ample time to re research space tech.