OP - not all games are from Nintendo. PS4 DQXI is there. duh. :P
Japan is really more of a handheld market now. With Switch hybrid setup, it is a win-win for them. And we know there could be more Switch iterations in the future and a single household could have more than 1 system compared to a home console. Lets wait and see how things would be in 2018. 2018 is the year Playstation would have a ton of great exclusives but I believe targeted more on western audiences, I still think it can get some good sales in Japan.
Not just the Switch is up though.
About DQXI, the 3DS version is on the list. It's on a Nintendo system, which is what was said.