They say it's out holiday 2015 exclusively for the xbox. So as of right now, you can only get it on the xbox. Once gamescom is over, we'll have more info. Just hold your horses. (this was my real response addressing this situation)
"Rise of the Tomb Raider, coming Holiday 2015, is exclusively on Xbox."
It's got punctuation to help separate each part and is worded perfectly fine. People are reading way too deep or trying to find something that actually isn't there.
If it's exclusive, just let it be, if it's not, who actually cares?
That's what i'm saying. Exclusives happen guys. It's not breaking news. You'll live, I promise. If they say it's exclusive and they haven't said ANYTHING about it being timed, than it's probablyyyy an exclusive.