The thing is . . . with an intact Hegemony, would any of the Royal formations go? If Kerensky goes with them, they would follow . . . or would they? In canon, they did because there was no Cameron heir, no First Lord. With the Star League falling apart, though, and a living Cameron at the helm of the Hegemony would the Royals abandon the worlds they had fought and bled to free from Amaris? Their own homes?
If, IF there is another Exodus, I would imagine it to be just regular SLDF formations raised from the member states, not the Royals.
I could be wrong.