MS will need to make console hardware for as long as console hardware is relevant to gaming. GP as a service isn't ready to go full cloud nor is the industry ready for full cloud services. GP is a service that download games on hardware that allows you to play your games. There is a reason that XCloud is only an add on instead of its own main service. MS recognized that the rest of the world including the US does not have the infrastructure for cloud only services not to mention the ISP and how they handle their internet services with metering and charging extra for going over data limits.
While GP is MS main focus for growth, in order for MS to achieve that growth, they need a hardware presence at this stage to continue to obtain and lock in consumers to their ecosystem. Just think about it now, you can get GP without an Xbox and run it from your android or Iphone. You can even screen share that to your TV if it has cast capability but who out their is even doing that. I tried it to see how well it looks and it looks like jank. So while MS could go all software subscription, without console hardware being able to show their games in the best of lights, the take up of GP will not be to the level MS require in order for the service to be profitable enough. GP is going to be an add on service for a while until MS can build enough successful IP where it can stand on its own. Until then, MS is a long way from obtaining that goal. ABK probably would help things move forward faster but not that much faster.
SO no, MS will be in the console business for as long as Nintendo and Sony. The difference is that MS will try to disrupt the market with GP and hope they can build it to be successful on mobile platforms as they continue to expand their gaming division.