Ninja Theory only mentioned PC and PlayStation 4 when they unveiled Hellblade: Senua's Sacrifice back in 2014. This obviously didn't stop people from asking about a possible Xbox One version. One of the reasons why they kept asking was that the developer's answer was always a different variation of "first to consoles on PS4", and it was never denied that the game could be heading to other consoles in the future. Now we know why.
The Australian Classification Board decided to rate Hellblade: Senua's Sacrifice yesterday. They didn't rate the game when it launched on PC and PS4 last August, so some might think it's just a belated update and not the first sighting of an Xbox One port. Taiwan's rating board seems to differ, however, as they've just rated an Xbox One version of the game.
Both of these rating boards have a reputation for revealing games in this way, so we're willing to venture that you don't have to take this with a pinch of salt. Now we just have to wait for the official unveiling of Hellblade: Senua's Sacrifice for Xbox One.