the directors for each game are different people, for FF13 and 13-2 it was Motomu Toriyama, and for Versus its Tetsuya Nomura, so game play wont be the same, plus they said there will be towns, dungeons, and open world, so i have high hopes for it :)
Edit: also i looked around some more and nowhere does it say that they are the same team XD, so im not sure where you heard that but i havent found anything that says the dev teams are the same XD