Unfortunately, Reborn Palpatine would have assumed command of Thrawn's New Empire had he been successful (let's face it, Thrawn was going to win if not for the Noghri).
I was re-reading this and was about to post this!
Thrawn is second only to Kyle Katarn as my favorite character. I wish he hadn't died as I would have loved to see a universe under his rule. I have a feeling it would have been the most stable galactic government that ever was.