100%. This has always been Microsoft's long-term strategy.
I agree that console hardware margins/profit are quite low, especially during the first 2-3 years. However, it would be a mistake for Microsoft to exit the console hardware space of gaming, IMHO. They haven't licensed the Xbox Gaming Platform (yet) in the same vein as Valve/Steam (i.e., Steam Machine/Box vendors) has, so there is no guarantees that an Xbox-Gaming-Only platform built by multiple vendors will work. Something Valve/Steam still hasn't cracked or truly gotten right. If anything, Microsoft will keep down same path within the PC space of providing Xbox Gaming Services through current and future OS integrations and iterations. But yes, I don't see them exiting the console space without a major shift from PC manufacturers towards providing a more unified platform/hardware experience, which a standalone Xbox console provides.
That being said, I can see Microsoft licensing Xbox Gaming Platform and streaming services through cable-TV providers (i.e., Comcast, WOW, AT&T, etc.), that can cover millions of paying customers. Microsoft can actually lead the charge with better gaming services with cable-TV providers whom provide communication services to the hotel and vacationing resorts industries. Have you seen/played the shi*** gaming services that hotels and vacationing resorts currently provide in their rooms? Microsoft, Sony, and Nintendo can vastly improve these experiences within these industries (including the cruiselines and airport/airplane industry).
I know about Steam Machine/Box vendors doing so. Are there manufacturers providing Xbox-Gaming-Only PCs (meaning, nontraditional PC OS, Xbox gaming only environment, simply a console masking behind beefier PC hardware)?
I'm pretty sure you can, but I haven't tried it.