At the end of Star Wars: The Rise of Skywalker, Rey gives herself the last name Skywalker, as a way to honor her teachers, and finally give herself the identity she was looking for. While Rey ends the newest Star Wars trilogy looking at the same Tatooine suns that Luke did, and taking on his name, she does have one thing that was unique to her, a yellow lightsaber. It's the first one we've seen in the films, and the first one wielded by a Skywalker, or so we thought.
The cover of the new book shows Luke with a yellow lightsaber. While the color had been seen before Star Wars: The Rise of Skywalker, in the Knights of the Old Republic video game series as well as Star Wars animated shows like The Clone Wars, seeing Rey carry the blade on the big screen seemed like a way designed to set her apart, since, like Mace Windu's purple lightsaber, we had never seen anybody else with it in the movies. That's still true, but the choice is now slightly less original.
Now, the fact that both Luke Skywalker and Rey have carried yellow lightsabers becomes yet one more thing that connects master and student. There's already a lot of negative response to this idea online from people who feel that giving Luke the yellow saber makes Rey feel less special.
While it's impossible to not see the connection between a movie and a comic book that have been released only two months apart, Charles Soule, the writer of the current Star Wars comic arc took to social media following the reveal to insist that giving Luke a yellow lightsaber wasn't influenced by the new movie, but instead had a much older inspiration, '80s toys.
This cover is from Star Wars #6, and issue #3 is only just now about to hit comic shops, so we likely won't know where this lightsaber came from until May unless it actually makes its first appearance in an earlier issue. Either way, there likely won't be a direct connection in the text between this lightsaber and Rey's decision to create a yellow lightsaber. Considering Luke's use of this color had to have been somewhat limited, there's no reason Rey would have known Luke had ever used that color.
Still, even if the lightsabers aren't directly connected, it is one more similarity between the Jedi master and his student who took his name.