We have been waiting for Kingdom Hearts 3 for quite a while and we will keep on waiting for the game to make its eventual release. The most recent reports suggest that the game will release sometime after April 2017, but no sooner than 2020.
When Kingdom Hearts 3 was first revealed back in 2013, it was revealed for the PlayStation 4 and the Xbox One. It looks like Kingdom Hearts 3 might not see an Xbox One release, at least not in Japan.
The Xbox One listing for Kingdom Hearts 3 was recently removed from Xbox Japan's website (via Reddit). Attempting to reach the page sends you to an error page that says the product might have been moved or the URL is incorrect. The official Japanese Kingdom Hearts III site still has an Xbox One listing and it is still up for pre-order on the North American Microsoft Store.
There is a chance that the Xbox One version of Kingdom Hearts 3 is canceled in Japan, especially when considering how big the PlayStation community is there in comparison to the Xbox community. Then again, the store page could simply be undergoing changes and could make a comeback.
