The way I see it both Xbox and Playstation win with that Tomb Raider deal.
1. Xbox gets to have Tomb Raider over the Holiday period
2. Uncharted 4: A Thief's End doesn't have the competition
3. 2015 is already shaping up to be something special for PS4 owners, so Tomb Raider coming out in 2016, might not be a bad idea.