The Jedi have long had a prophecy that states that ""A Chosen One shall come, born of no father, and through him will ultimate balance in the Force be restored." This is why, in the Star Wars prequels, the Jedi believed that Anakin was the Chosen One, since he had no father and was strong in the Force.
Of course, Anakin ultimately turned to the Dark Side and joined the Sith, dashing the Jedi's hopes that he would fulfil the prophecy. Many have wondered if Rey may turn out to be this long-awaited hero, and her arc in both The Force Awakens and The Last Jedi seems to hint that she feels equally drawn to both the Light and Dark sides of the Force.
However, what if the film's title refers not to Rey herself, but to a brand new order of Force users, who are able to use the Force in perfect balance? Not only would this circumvent the Chosen One narrative, but it would fit perfectly with the previous two titles. Now that the Force has awakened, and the last Jedi is gone, perhaps that clears the way for "Skywalkers," Force users like Rey who are able to tap into both of the opposing sides of the Force and harness that power for good, instead of losing themselves to one side or the other.
Note that the prophecy never stated that the Chosen One would be the one to bring balance to the Force himself; it said that through him, balance would be restored. Remember that Rey received her Force instruction from two Skywalkers: Luke and Kylo Ren, each focusing on a different side of the Force. If she is the one to bring those sides into balance, and the one to begin and name a new order of Skywalkers, then Anakin's line did, in fact, fulfil the prophecy.