For jumping the shark I'm speaking about bringing back a character clearly intended to be dead in the OT. Yes, I'm looking at you Rise of Skywalker. I know the EU did it, and I didn't like it there either. I didn't mind the cloning angle of bringing Palpatine back in the EU which, unlike RoS, made sense. I wasn't a fan of Terminator Maul either, though they handled the stories with him well in the cartoons. In all cases bringing back these dead characters was convoluted, confuses more casual fans and shows a real lack of creativity.
Mostly I want The Mandalorian to continue to establish its own cool villains. So far they have done a great job of adding new characters to the SW lore I want to know more about and see more of. They are expanding the universe, not confining or shrinking it as RoS did. Keep building, keep growing, keep creating. They have set up more than enough new content to not have to resurrect a dead character for story ideas.