http://gematsu.com/2016/07/final-fantasy-xiii-spotted-xbox-oneFinal Fantasy XIII might be coming to current generation platforms. A product page for the game was discovered on Xbox.com, which is no longer working, but if you have an Xbox Live account, you can sign-in and compare Final Fantasy XIII achievements for Xbox One with this user, which directly links to the broken page and displays the box art posted above.
Square Enix has yet to announce a current generation version of Final Fantasy XIII, which is currently available across PlayStation 3, Xbox 360, and PC.
I know in China, FF13 is out for XB1 via cloud streaming.
http://neogaf.com/forum/showthread.php?t=1210826