IMDb has The Great Wall's budget at 135 million, pretty large. It also has 2 different Skull Island movies listed. One is the just titled SKULL ISLAND, starring Tom Hiddleston and the other is called SKULL ISLAND: BLOOD OF THE KING with the following description. "25 year after King Kong's death in New York, Carl Denham's son runs an expedition to Skull Island and tries to to solve the decade long mystery." The Blood of the King movie lists Legendary pictures as the production company. Perhaps those 2 SKULL ISLAND titles are the same movie, and maybe the delay had nothing to do with timing but instead a case of creative differences over the direction of the story?