According to the post on Reddit, “I was looking through my achievements out of boredom when I noticed this. Seems that Tekken Tag 2 will be coming to Backwards Compatibility as the boxart has been resized similar to other BC games. Update: Several people have told me they have managed to download it and play so yes, it’s official guys :)”
We don’t have the Xbox One so we aren’t able to confirm this for ourselves. Neither Microsoft nor Bandai Namco have come forward to confirm it either. Microsoft has yet to reveal the list of Xbox One backwards compatible titles for the month of January, but if the posts on Reddit are any accurate, we can assume that Tekken Tag Tournament 2 will be one of them.
In the meantime if you do own the Xbox One, then you can go ahead and check it out for yourself if you are so inclined.