In the real world there are still admirers of the losing side in a certain World War, so that somebody idealizes and tries to recreate the Empire doesn’t surprise me. There were probably some systems that had it pretty good under the Empire, and would welcome a return to those days.

There was no way the entire Imperial fleet was at the battle of Endor, nor meekly surrendered once the Emperor was dead. Even Robot Chicken has pointed this out.
https://www.youtube.com/watch?v=mAOX_CHU0JY

And the wrecks on Jakku are proof that there were still battles fought for some period of time until a cold war style stalemate settled in.

The old Marvel comic tried having a larger alien threat move in on the Galaxy post ROTJ. It simply wasn’t as interesting as the Rebellion/Empire conflict. I did like the idea of the remaining Imperial forces joining with the Rebellion to fight the new bad guys. The conflict in Star Wars has always been the backdrop that smaller more personal battles play out in front of.

Or do we want another Trade Federation dispute? 😉