Well I’d say whoever would be bought by Xbox would have a stigma attached. The developer would be a laughing stock in their country making games just for Xbox.
And why do that when Konamis game developing potential took a nosedive? They are just a gambling machine company that happens to own 3 iconic game IPs now. Thats why its at the very least more plausible then your average poorly written April fools joke. Still fun regardless to wonder just how Ms gonna enter the Japanese developer market.
There is zero plausibility to this rumour because Konami makes over 50% of their revenue from their gaming division.
Of their 192million yen in revenue in 2018, gaming accounted for 105million. For 2019, it was 108 million.
Gambling is only their 3rd biggest profit mover (after fitness and gyms and only narrowing their arcade business) accounting for 21 and 22 million, in 2018 and 2019 respectively.
Sony licensing their games has more credibility than this rumour (which btw has existed before the Sony rumours).