Star Wars: The Rise of Skywalker toys with the idea of killing two beloved legacy characters, but isn't brave enough to go through with either one. Though J.J. Abrams said he was open to taking more risks on the movie, he didn't completely go for broke at two key junctures. Early on, Rey appears to accidentally kill Chewbacca with Force lightning as she wrestles for control of a First Order transport with Kylo Ren. However, it's revealed moments afterwards the Wookiee was on another ship and is still alive and well. Later on, when the main group goes to Kijimi, they need to wipe C-3PO's memory so he can translate writing on a Sith dagger. But when Threepio returns to the Resistance base, R2-D2 restores his memory to return everything to normal.
Fake-out deaths are nothing new in Hollywood (including the Star Wars franchise), but The Rise of Skywalker takes the trope to its absolute extremes. Abrams presents the presumed demises of Chewie and Threepio as major emotional moments in the story, though undercuts their impact by backtracking on them. When watching the film, it feels like Abrams wanted to swing for the fences, yet was afraid of dealing with the greater consequences of doing so. Many fans were no doubt happy Chewie and Threepio lived to the end, but The Rise of Skywalker is arguably better if they don't.
In the case of Chewie's "death," the scene is meant to illustrate Rey tapping into her natural dark side energy to gain the upper hand against Kylo, not realizing the full extent of what she's capable of. The sequence still accomplishes this, demonstrating what Rey could become if she doesn't control her power, but it doesn't pack as poignant of a punch. Rey was clearly rattled when she believed she had killed one of her best friends, terrified further by her foreseen fate sitting on the Sith throne. This had the potential to be a moment similar to Luke considering killing Ben Solo in The Last Jedi - a deep, personal failure that fueled Rey's (temporary) decision to choose a life in exile on Ahch-To. If Chewie's death had been permanent, the Rey Palpatine reveal may have been more devastating, implying Rey accidentally killed Chewie because of who she is. Again, the surface-level point (Rey can do terrible things if she isn't careful) comes across, but it lacks something more because the scene's greater repercussions are stripped away.
Threepio's "taking one last look... at my friends" line was a tear-jerker in The Rise of Skywalker's final trailer, but ultimately rings hollow. Abrams almost immediately weakens the notion of Threepio's noble sacrifice by establishing Artoo has a backup in his system (complete with an obvious red herring about its unreliability) in the same scene. Just the very idea there might be a way to restore Threepio to his old self afterwards undermines the protocol droid's willingness to go through with the procedure to ensure the Resistance's mission will succeed. It's nice that after 42 years, Threepio got his heroic moment (and Rey's "You know the odds better than any of us" line was a sweet touch), but like Chewie, the scene probably stands out more if Threepio's memory wipe was permanent. If nothing else, Threepio's brief interactions with Artoo would have been more emotional.
These two instances are a case of Abrams trying to have his cake and eat it too with The Rise of Skywalker. There are few risks filmmakers can take bigger than killing off iconic characters, and there's no denying if these had stuck, they would have ruffled some feathers. But in a way, it's more frustrating to tease such drastic events, only to pull back shortly after. That minimizes the stakes and cheapens the drama of the story. Star Wars is a family-friendly franchise, but it still deals with galactic wars and it's important for there to be meaningful consequences during times of conflict. Saying goodbye to Chewbacca and C-3PO would have been very tough, but no harder than bidding farewell to Han, Luke, and Leia.