The following contains spoilers for Dark Knights of Steel #7, now on sale from DC Comics
In the timeline of Dark Knights of Steel, there have been plenty of changes from the traditional DC canon, including the origins of Superman, who in this world never grew up without his birth parents. But one of the most important elements of his origin has been secretly at the heart of this world all along -- just with a different hero.
Dark Knights of Steel #7 (by Tom Taylor, Nathan Gooden, Arif Prianto, and Wes Abbott) confirms that while the Kents didn't become Superman's parents in this reality, they did have a hand in protecting and raising Aquaman, proving their importance in the DC Universe.
Jon and Martha Kent were formally introduced in this fantastical reality in Dark Knights of Steel #6. In this reality, Jon and Martha didn't raise Kal-El, as his parents both survived the trip to Earth. Instead, the Kents, who served as soldiers in the Wayne army, had a mission to protect empowered peoples who would otherwise be threatened by the world. This includes Bruce Wayne (who the couple discovered following a surprise attack from the Superman of this world) and the Teen Titans of this timeline, who've been in hiding on Kent's farm. Following a massive battle between the Kents, their charges and the newly arrived Ra's Al Ghul/Etrigan fusion, the Kents reveal which notable hero was the first one they took in and cared for.
Jonathan Kent explains to Bruce that years earlier, they accepted a child of "two worlds," the son of a man from land and a woman from the seas. According to them, "Arthur" was initially concerned about his place in the world, but after time with the Kents, Arthur embraced his destiny and became a great king. This is a clear reference to Aquaman. It's an interesting deviation for this reality to take, and one that works on multiple levels. It's a clever way to address where Aquaman is and what he's been doing. It establishes that Aquaman is at least a bit older than most of the primary heroes and villains of the series, as he's been cared for by the Kents, rediscovered his roots, and earned the throne of Atlantis completely off-panel before the events of the current series.
Having Arthur Curry be close to the Kents and thereby influenced by their teachings is a big deal. This highlights their importance in this universe despite their nominally human role. This could make Aquaman a crucial ally going forward, as he could likely serve as an intermediary between the nations barreling towards open conflict. The other interesting element of Aquaman being given Clark Kent's origin is witnessing the effect it has on Superman as well. While Kal-El's origin will always feature his survival from the planet Krypton, nothing had more influence on Clark's character than the Kents. It was their teachings that transformed him into the hero he is in most universes. Their influence turned the most powerful man in the world into a true hero able and willing to fight against injustice.
The Kents note the humility they taught Arthur, and it's clearly had a positive impact on the ocean king. That is compared to the Els of this timeline, who are portrayed as noble but removed from humanity. While Superman and Supergirl's analogs have been shown to have good hearts (that are either being manipulated or impersonated by some nefarious force to cause war), they still remain somewhat removed from the world they're a part of. Without the Kents, Superman never gained the humanity that has long defined him and made it possible for him to be a hero instead of a tyrant. Even if he isn't a villain, he's clearly not the same hero he would have been under the Kents' influence -- speaking to the importance they truly serve in the growth of Superman as a hero.