There is indeed a lot going on in Star Wars: The Rise of Skywalker.
Unfortunately, this information will probably end up coming out some other way, perhaps in the Star Wars novelizations or eventual comic book adaptations yet to come.
Now, thanks to the movie’s editor Maryann Brandon, we know that even more Palpatine footage didn’t make the cut, and it sounds like important information.
Maryann Brandon also says there was “a little more information about it, what was keeping [Palpatine] alive,” but said, “it seemed to go off-topic.”