Development cycle is the least of my worries.
There are a number of reusable assets from Final Fantasy XIII, an unprecedented amount of cut content, and the entire framework established by the previous game. A reduced development cycle is hardly a surprise, and frankly, because Square Enix is so notoriously bad about sharing information with its fans, we have no idea when development on a sequel began in earnest. Given that even the battle system seems to remain largely unchanged, I'm not surprised that they're burning through this.