I don't understand why people think that the Empire would just disappear after Jedi. That idea never occurred to me at all. I figured it would be a given that we would see them again, albeit in a very weakened state.

It's strange that so many people were torn up about losing the canonicity of post-Jedi EU like the Thrawn Trilogy, and yet there are people who are just as annoyed that the Empire is still alive and kicking when basically all post-Jedi EU included the Imperial Remnant in some form. You can't just end a galaxy-spanning governmental body by killing its leader (look at the United States, that, while not galaxy-spanning, would certainly have been gone long ago if all it took was waxing its leader); I'm sure one of Palpatine's inner circle or some ambitious Admiral or someone stepped into the power vacuum, and even if the Empire lost control of the galaxy and a New Republic was formed, then I'm sure there's some Imperial holdouts or some Neo-Imperial revival somewhere in the galaxy that holds true to Palpatine's ideals.

I'd love to see a tables turned scenario where the ex-Imperials are now the rebels and the New Republic becomes the beast it once fought against. It's a very "Lucasian" plot device and would bring up lots of interesting questions for Leia (who will undoubtedly occupy some form of leadership role), and moreso Luke. Perhaps he left the Republic when it became an engine of destruction, dedicated to hunting down and exterminating all Imperial holdouts.

I feel like the Empire deserves to still exist in some form, with all the build-up from the two existing trilogies to be dealt with on-screen rather in a footnote in some yet-to-come encyclopaedia.