If i am honest. MS should stop with trying to make Xbox work in Japan. It will never happen. Getting a studio wont fix it also.
Instead make sure Japan devs release games on Xbox. Like Spencer said himself many times.
While I'm (perhaps foolishly) optimistic that MS can gain some traction in Japan next gen (through the potential of GamePass and xCloud), I would be perfectly content knowing Xbox will get the same non-first party Japanese games Playstation gets.
I know we are almost there in many aspects, but there are some glaring omissions. Not getting the Ni No Kuni remaster was a punch in the gut. I would love to have FFXIV on Xbox consoles, but after years of speculating, I don't expect it anymore. The Yakuza series, while not my cup of tea, would be a great addition. The Tokyo RPG Factory offerings would be great additions to GamePass. I know Dragon Quest is a pipe dream, but it would fill a major hole in the Xbox catalog.
I believe that with enough time and resources, Xbox could be synonymous with WRPGs next gen due to their acquisitions. If higher ups focus on making sure Japanese studios don't ignore their console, Xbox could be be poised to become a premier place to play RPGs of all styles (WRPG, CRPG, ARPG, JRPG).
A few years ago, I would have laughed at the notion. But today, I can see that path.