Microsoft signed a 'parity' clause with RGG studio, which states that if RGG studio (or likely Sega entirely?) release a game for PlayStation, they must also release it for Xbox. I'm unsure if this extends beyond Yakuza games, (The documents were about RGG studio/ Yakuza Like a Dragon specifically) but it makes sense as to why Xbox is getting Persona ports and Unicorn Overlord from Vanillaware, but is skipped on Switch exclusives likes Etrian Odyssey collection and SMTV.
Nintendo's Sega exclusives weren't targetted or included in the clause, just PlayStation's.
With this news, Xbox will most likely be getting Persona 6 day one. It also goes to show MS's mentality: Undermine and destroy PlayStation's 3rd party relationships, by FORCING developers to support Xbox too, if they support PlayStation
This is a pretty damned devious deal and must have cost Xbox hundreds of millions of dollars. MS also sweetens the deal by paying a lump sum for gamepass inclusion, which negates the possible (and let's be honest -- likely) sales failures of these games on the Xbox platform.
Well, there it is.
TL,DR: Microsoft has signed a Parity clause with Sega moving forward from ~2020 that states if Sega develops a game for PlayStation, they must also develop it and release it for Xbox.