It’s an option. But if you remove Palpatine entirely you lose the majority of TROS. There’re probably some that can be used elsewhere, but you’re more looking at butchering TROS and putting elements of it into a changed TLJ, than retaining a three movie structure. You potentially could drop the entire Canto Bight plot if you needed to make space for new content. The challenge then is in finding a solid conclusion to the duology, making TLJ’s ending serve as the series ending - which as in my original post on this idea, I reckon you can only really satisfy with a Rey/Kylo confrontation.