A new Star Wars: The Rise of Skywalker leak suggests a flashback scene will play with "our perspective" on the events in the latest trilogy. When Carrie Fisher passed away at the end of 2016, many were curious how Leia Organa would continue to be portrayed on the big screen. She had already finished her work on The Last Jedi, so that movie was fine. However, when it came time to announce The Rise of Skywalker, Lucasfilm revealed they would be using unseen footage from The Force Awakens and would not be using another actress or digital effects to take her place.
With that being said, the latest leak suggests that Carrie Fisher's daughter, Billie Lourd, has shot a flashback scene for The Rise of Skywalker as Princess Leia, which takes place after Return of the Jedi. It is believed the scene will include Luke Skywalker and Leia, though it isn't clear if Mark Hamill will be playing himself with de-aging technology or not. The scene in question reportedly, "plays with our perspective" on the latest trilogy and helps to explain some lingering questions.
A young Luke Skywalker and Princess Leia allegedly have a talk about the future in The Rise of Skywalker. Luke went on with training young Jedi, while Leia became a mother and later a general after Return of the Jedi. It is believed Leia sees something "problematic" about her future if she trains to be a Jedi. "Some kind of vision, premonition, or warning plays" a part in both Luke and Leia's decisions towards the future, much like Luke almost murdering his young nephew in The Last Jedi flashback scene. However, this information is coming from anonymous sources, so it's best to treat it as a rumor for now.
It has been rumored since 2015 that Billie Lourd was going to play a young version of Princess Leia in the latest trilogy and it has yet to come true. This could be where the original report is coming from, but they seem to be pretty adamant about it this time around. It is not believed Harrison Ford will be involved in the flashback scene. Instead, it is rumored that his part is completely separate and takes place in the present. Whispers about Alden Ehrenreich possibly showing up in The Rise of Skywalker are more than likely false.
With The Rise of Skywalker being the final movie of the Skywalker saga, some flashback scenes certainly make sense. Legendary composer John Williams recently revealed he has about 25 minutes of new music for the movie and he liked what he saw a lot from an early cut of the movie. During the first trailer, we get a tease of Leia's Theme, which originated in 1977's A New Hope, so it's safe to assume the music will get some flashbacks too. J.J. Abrams has a lot of loose ends he needs to tie up. This news comes to us from Making Star Wars.