For right now it's been confirmed that XCOM 2 is only scheduled to arrive on PC as an exclusive. However, it might be a timed exclusive because the developers haven't completely ruled out a release on Microsoft and Sony's eighth-gen consoles.
According to an interview with IGN, creative director Jack Solomon mentioned to IGN that the team at Firaxis Games aren't opposed to porting XCOM 2 to home consoles but at the moment they're just focused on the PC. Why? Because they can't afford to be stretched thin working on a multiplatform game and trying to scale the assets and features from PC to PS4 to Xbox One. Firaxis is a small team and they want to work on doing the best they can with the capabilities and power of a PC.