I'm not sure if they're as strict on that as Nintendo and Sony are. Eventually Nintendo did release mobile games, didn't they? But Microsoft ain't ever going into the handheld market or something, outside of the Windows Phones that are no more. Also, they have a lot more to lose than Sony by releasing their games on Steam, including Halo, rather than exclusively on their Xbox Live subscription ecosystem, but they do.
Age of Empires thrived on the PC ecosystem too, it was Microsoft's Halo before Halo. Viva Pinata, uh, struggled, so yeah. But it was kinda of prolific, probably Rare's most prolific franchise under Microsoft until then... which is sad lmao. I give you that one. But yeah, I don't think it's as impossible as Mario on Playstation, not at all. But of course, there are lots of "buts".