The problem with leaving in “I am all the Sith!” is that Rey’s new “I’m a Jedi!” response has to specifically be to Sheevie’s “a SCAVENGER GIRL is no match for the power in me!” statement, right? (edit: just as the poster above said!) Perhaps swapping Palpatine’s lines would work. Here’s a crude mockup of that idea (forgive the unpolished audio and lack of ghosts).
This is perfection and would be a mistake not to include.