I think if they felt Palpatine had to return in some form, I would’ve preferred the conflict would’ve centered around a Sith cult trying to resurrect him, and the protagonists are trying to prevent that, rather than him already returning in the flesh.

Something the movie introduced that I felt they should’ve leaned into more was the idea of Palpatine being some kind of Sith hive-mind. It at least would’ve made Palpatine, as an antagonist, feel different than before. I recall there being speculation about this very idea in the past, because both the Darth Bane and Plagueis novels hint at this idea of spirit possession. So maybe in IX, instead of the villain being “Palpatine”, we get to see this hive-mind in its true form.