I just think the whole game won't be that predictable. Also, rarely does the main motivation in the beginning of the game never change in a FF game. Where you are at the end is almost never where you thought you'd be in the beginning of your quest. While motivations remain, priorities change. We still don't know most of the villains' motivations other than "power hungry", which I doubt it's that easily defined. There's probably a reason why they want Lucis' crystal, and something dark conspiring in the shadows within Niflheim itself.