As the grand finale, The Rise of Skywalker makes some big decisions about the Star Wars universe, both in regards to the past, present, and future of the franchise. Not only will upcoming works be radically different, but watching the older films with the knowledge of what comes after also changes the viewing experience.
To drive this point home, the following list will detail ten ways the new movie completely changes Star Wars. Thankfully, none of these completely ruin the franchise, so even if one doesn't fancy the sequels, they can still look back at the original trilogy as the masterpiece it always was.
Rey's Lineage
Throughout The Force Awakens Rey is in the dark about her past. She has no memory of her parents, only vaguely recalling them flying away on a ship. In the sequel Kylo reveals their status as nobodies who sold her for some junk. Rise of Skywalker sets the record straight once and for all, however, revealing her father to be Emperor Palpatine's son, making Rey his granddaughter. One can call it a retcon, but Palpatine also could have been feeding this lie to Kylo through the Force. While some may have preferred it if Rey remained without a legacy, the film still runs with an interesting theme about turning your back on destiny to do what's right and forging one's own path to righteousness.
Destroying The First Order
The tangible menace plaguing the Galaxy throughout the new films is the First Order. It is not exactly clear how they came to power, though Palpatine's work from behind the shadows probably had something to do with it. Whatever the case, they won't be hurting anybody anymore after Rey and the Resistance's glorious victory over them at Exegol. The whole galaxy chips in to send them running, destroying the evil army's greatest weapon - making people think they are alone in the fight.
Snoke
One of the biggest mysteries surrounding the First Order was the identity and background of their enigmatic leader, Snoke. Fans were shocked when Kylo disposed of him in The Last Jedi, and the first scene of the new movie immediately explains where he came from and what his goal was.
The Supreme Leader the First Order so admiringly looked up to was nothing more than a clone created by Palpatine. He wasn't half bad at making them, either, considering how far Snoke got in his scheme to control the Galaxy.
Leia's Jedi Training
As a Skywalker, Leia's sensitivity towards the Force is a given. Her abilities are shown to be much stronger than initially thought when she floats back to safety from outer space in The Last Jedi. Rey's first scene of the new film shows her training under Leia's direction, and Luke's scene contains a flashback showing her training with him after the events of Return of the Jedi. She gave up her training, however, though apparently had enough experience to do some impressive force moves of her own later in life.
Showing The Sith's Hidden World
Despite their status as the ultimate villain of the franchise, the Sith remained a mysterious group throughout the nine films. The only real force of evil from them seen is Palpatine, and he reveals little about his past. Finally, The Rise of Skywalker shows audiences their hidden world, Exegol.
Kylo Ren first steps foot on the world in the introduction, and then Rey and company find their way to it for the grand finale. Seeing their architecture reveals more about the Sith then any of the prior media before ever did. Though the mysterious people worshiping, chanting, and working for Palpatine adds yet another layer of mystery about them and the planet.
Kylo's Corruption
Throughout the two prior films it was thought to be Snoke planting these ideas in Kylo's head. Palpatine immediately washes this notion away to reveal it was him feeding the words and thoughts to Leia's son since the beginning. While it is cool to see the Emperor back, it does lazily to shoehorn the villain in there when neither of the preceding stories had any foreshadowing whatsoever.
Rey And Kylo's Relationship
Kylo always felt some kind of connection with Rey, but it was never known precisely how. Even Palpatine, with all his knowledge and power, was in the dark about their true relationship. They ended up being a dyad in the Force, two people joined by their sensitivity to the mysterious power, essentially making them one in the eyes of the Force.
This explains how they were able to communicate across planets as if they were in the same room. It made for one of the cooler duels of the series where they locked sabers while in physically different spaces, breaking things in each other's rooms that crossed into the opponent's space.
All The Skywalkers Are Gone
The nine movies have been dubbed as The Skywalker Saga because it tells the story of the family lineage from Anakin all the way to Ben Solo, or Kylo Ren. By the end of the The Rise of Skywalker all of them are dead and gone. As sad as this is to realize, at least Rey carries on the name, though she is not related by blood. This is a central theme of the last movie, however, as the main character turns her back on her own family lineage and destiny.
Destroys Palpatine Once And For All
For nine movies and over forty years Palpatine has controlled events, mostly from the shadows. He was thought to be down for the count in Return of the Jedi, but not even falling down an endless pit can stop an all powerful Sith Lord. Rey really does a number on him, though, quite literally turning him into nothing but mush and dust. Not even the most powerful being in the Universe can come back from that.
Making Clone Jedi Possible
The now non-canon Force Unleashed dealt with the question of cloning Jedi, something which was thought to be impossible. While only a footnote on a busy movie filled with numerous plot points, Palpatine's usage of Snoke clones seems to imply that cloning a force sensitive being is possible. It brings up another question, though. Was there ever a real Snoke who served as the blueprint for the clones, or was he created from scratch?