I would prefer that they not do this.
When Carrie Fisher passed away late last year, there was a lot of speculation about whether or not she’d appear in some way in Star Wars: Episode IX. Her role in the upcoming Star Wars: The Last Jedi had been completed before her death, but the next film had not yet begun shooting. Her brother Todd Fisher told The New York Daily News that he and Fisher’s daughter Billie Lourd have given Disney and Lucasfilm permission to use recent footage of Carrie Fisher in Star Wars: Episode IX.
My objections are relentlessly practical, however. Unless they’ve gotten extremely lucky, Disney has a bunch of footage that needs to have the rest of the movie written around it, as it were. Maybe they’ll only have to write around it a little. Maybe they’ll have to write around it a lot. No matter what, it gives off the feel of a gimmick — and that will make the movie just a little less watchable. Sometimes you need the gimmick anyway (the CGI character resurrections in Rogue One spring to mind). And sometimes you do not. I think that this might be a ‘not.’