With Vegapunk saying that “the fate of the world will be decided by whoever finds the One Piece,” and the panel that shows all the major factions in play, it’s basically confirmed that the final war is all about the treasure. This is the same war Whitebeard was talking about. He added that once the treasure is found, the world will be turned upside down. But how can anyone think he meant another war? All the stakes and all the forces are already on the board. The conflict for the One Piece is the final war.
(For example, imagine if we see GV and Haralds story after the SHP fought Imcel this arc...)