Here’s a weird idea: change 3PO’s line about the OLD Republic banning speaking Sith to the NEW Republic. (Maybe have to remove “I believe” since it’d be recent.)
Idea is that it’d make the hindrance due to recent hubris or myopia, and remove a slight implication that Palpatine being a Sith would have been in and of itself unacceptable in the days leading up to the Empire. (Like the novelization of ROTS maintaining that belonging to the religion Sith isn’t a crime.)