Emperor Palpatine using The Force to yeet himself into some kind of safe room and them be worshipped by disgusting, emaciated Chaos Ewoks due to climate change from the Death Star wreckage is so fucking, fucking awesome.
I'll go one further. Whatever power source the Death Star had, when it rained hell down across the planet it also mutated the wildlife and Palpatine draws strength from some burning Chernobyl-like fragment of the core. I imagine mutant Ewoks with six-inch claws and razor sharp incisors, covered with tumors and scaborous tissue poking out between their fur.
Maybe have a village of the original Ewoks that have still mutated but only a little. They're still friendly looking, but they're a less derpy design now. They can be found in some Hobbit-like idyllic hideaway by the heroes. Maybe they even have a comedic The Tell of Captain Walker-like scene where they try to retell the original trilogy in some horribly misinformed way, and the audience is laughing along with these little weirdos and having fun, then someone asks "What happened after that?" And the music quiets down, and the little guys all have thousand-yard stares and everyone just stays silent. Perhaps one elder that still looks like the old design takes a swig of Gzorbo hooch or something to punctuate the scene. And they don't want to fight because the mutant horror Ewoks killed all the other tribes, but they show up to save the day at the end.
Fucking aye, I'm not even a Star Wars fan and I'm already coming up with ideas for this thing.
Edit: Goddamnit, I had another one.
Perhaps Elder Ewok is the big deciding factor, and the younger mutant Ewoks want to take the fight back to the Chaos Ewoks. But the Elder and the older warriors keep saying no, no, no, its all in the past, we need to keep our heads down, I don't care if they can use the force, etc. Then Luke The White shows up. (Or maybe have Luke wear black just like in Return of the Jedi? Maybe have him dress in the hood too so he resembles Palpatine?) Confronted by a figure from their mythology, the Elders are forced to back down and Luke uses them as backup for the main heroes while he takes the fight to Palpatine's throne or whatever.
Lando's up in space with the Falcon fighting a First Order fleet, he even yells out something like "We've got to give them more time!" like in Jedi. Come on, this pandering writes itself. Have the friendly Ewoks go up against a bunch of landing First Order stromtroopers, except this time they have like, Mad Max style post-apocalyptic tech. Like spears tipped with Death Star shrapnel. Take the opportunity to show them really go First Blood on the Storm Troopers with like, pit traps and stuff. Or they make adorable little IEDs out of old blaster batteries and space lightbulbs. Something. Come on. I can write this shit.
There. There's your No One is Ever Really gone. No time travel required.
