I'm gonna preface this by saying this is a bit of a passionate subject for me, so I apologize if I come off as dismissive or rather blunt.
If MS buys a Japanese dev, there is little to no reason not to put whatever game they make on Switch (outside the switch not being able to run it).
1."But Zeta, what if they are trying to attract a new audience by finally getting exclusive Japanese games?"
They tried that. It didn't work then and it definitely isn't gonna work now.
2. Could you really imagine being developer working on a project your passionate about, then waking up everyday and realizing no one who plays games in your entire country gives a shit about what your working on because it's exclusive to a platform no one cares about where your live?
3. Everyone who mains eastern developed games already has a PS4 or a Switch because at this point it's common sense that that's where you go for those types of games. That's not gonna magically change for Scarlett and PS5 just because MS might get an exclusive. So if your looking at this from MS's perspective, what makes more sense?
a. Keeping your Japanese developer locked to exclusive releases on Xbox for the chance of getting an audience typically averse to your platform in the first place to buy hardware for maybe 2-3 games tops for the entire gen...
Or
b. Allowing the dev to release on Switch as well as PC (with crossbuy/crossplay/ All that good stuff) to ensure that that particular audience gets access to your game without dropping money on hardware and as a result, get way more software sales than a Xbox exclusive Japanese developed game ever would, and if it includes the hooks that stuff like Minecraft on Switch does, more MAU's that may actually invest in your ecosystem now that they have easy access.
I know list wars mean a lot to certain people but I'm having a hard time seeing how switch releases if a Japanese dev comes into play would have negatives that outweigh the positives. And I say all this as someone who thinks there is a place for Japanese games on Xbox and that they can do well on the platform (Nier: Automata & FFXV both come to mind) but I'm tired of Xbox trying and then we as gamers get stuck with gems that never get follow ups because it wasn't the success MS wanted. Like can you imagine for a second if these games had gotten the proper treatment and success they probably would have got on other platforms?
We should be on Lost Odyssey 3 by now.
We should be on Blue Dragon 2 by now.
D4 should have gotten finished.
Crimson Dragon shouldn't have been a damn Kinect game and we should have a proper spiritual follow up to Panzer Dragoon Orta by now.
Ninety Nine Nights shouldn't be dead right now.
We would have spin offs to Phantom Dust by now.
Don't get me started on Scalebound.
It has sucked to be a fan of Xbox and Japanese games since the first years of the 360. I would really hate to see another attempt fail cause at the end of the day, I want to see good games get treated as such instead of being tossed in the trash and forgotten about like so many of Xbox's past attempts.
/End rant