It's the same universe but The Last Guardian is very different from Shadow of the Colossus. But it's made by the same guy - Ueda. I envy you though - next year you'll be playing SotC for the first time. You're in for a treat. You've never played a game like it.
I wouldn't bet on it if I were you
Bet Shiken that COD would outsell Battlefield in 2018. http://gamrconnect.vgchartz.com/post.php?id=8749702