Timothy Zahn is a legend in the Star Wars franchise. In 1991, Zahn's "Thrawn Trilogy" essentially launched the old Expanded Universe. He created the galactic city-world of Coruscant, which George Lucas used in the Prequel Trilogy, and Star Wars: Rebels has brought a number of his favorite characters back into the new canon - most notably Grand Admiral Thrawn himself.
Zahn's latest novel, Thrawn: Alliances, explores the relationship between Thrawn and the Dark Lord of the Sith, Darth Vader. The book is divided into two eras; one sees Thrawn's first encounter with a Jedi Master, Anakin Skywalker, in the dying days of the Clone Wars. The other is set shortly before A New Hope, with Palpatine sending Thrawn and Vader on a mission together. Naturally, the two stories are interwoven, and they reveal a whole new Force-power - one that redefines the Skywalker legacy.
In order to understand this new Force-power, you first have to understand a more familiar power; the Jedi's ability to swat blaster bolts aside with ease. Zahn's novel establishes that Jedi can do this because they have a degree of precognition, experiencing what he refers to as a "double vision." There's a split-second in which a Jedi sees both present reality and future threat; this glimpse of the future allows a Jedi to move their lightsaber in position to block a blaster bolt, or to move with preternaturally fast reflexes when facing a physical attack. It's a smart explanation of a basic Force-power, but Zahn then takes this one step further; he introduces the Force-power known as Skywalking.
The bulk of Thrawn: Alliances is set in the Unknown Regions, a place where hyperspace is warped and distorted by supernova chains and perhaps even a collision with a galaxy of dark matter. The spacetime warps created by fluctuating gravity masses make it incredibly dangerous to travel through hyperspace into the Unknown Regions; there are no stable hyperspace routes, and a single mistake can mean your craft crashes into anything from a stray planet to a neutron star. The only safe way to travel through the borders of the Unknown Regions is with a Force-sensitive. Just as a Jedi predicts an incoming blaster bolt, so a Force-sensitive can predict the imminent threat of a gravity mass. Just as a Jedi swats a blaster bolt aside, so a Force-sensitive pilot can maneuver their vessel away from the danger. The Chiss refer to a Force-user who can do this as a "Skywalker," and that prompts a rather amusing reaction from Thrawn when he first meets Anakin Skywalker.
Among the Chiss, only a handful of children - all girls - are born with a sensitivity to the Force, and it weakens with age. That's why, towards the end of Thrawn: Alliances, Grand Admiral Thrawn places Darth Vader in control of his ship. Darth Vader becomes a literal Skywalker, piloting the Chimaera through the turbulent borders of the Unknown Regions in order to pursue the threat of the Grysks.
The Skywalker Name Has Always Been True
The irony, of course, is that this deeper meaning to the Skywalker name has been baked into the Star Wars franchise from the start. In A New Hope, Luke turns off his targeting computer during the Death Star run. In that split-second, though Luke doesn't know it, he's blending the use of the Force with piloting - and becoming a true Skywalker. The Empire Strikes Back saw Luke find his own way to Dagobah, piloting the X-wing manually - without putting through any calculations for a hyperspace course. It seems likely the reason Anakin was considered "the best star pilot in the galaxy" is because of his instinctive blend of the Force and his own innate piloting skills.
This, then, is the smartest kind of retcon. It fits perfectly with everything we've seen in the canon, but also adds a new layer of meaning to an established aspect of the canon. It seems both Anakin and Luke really were Skywalkers after all - and not just because of their surnames.