You mean like an Admiral Thrawn or Admiral Daala types commanding a decent force loyal to the empire, not around when this all goes down. But then they come back and rally the remnants of the Empire Possible for sure, however I highly doubt there would be a galaxy wide war for thirty years on the level of the clone wars we saw in the PT. No, somebody will have the upper hand in the ST, and I highly doubt it will be the remnants of the empire. I think Zahn's first trilogy was a good variable way to look at what would happen to the empire, after the rebels won. Lucas after all had to agree to this.