First off, there is no 10 year limit, but I’m too tired to detail why…again. LOL
But just for fun, if next week, MS decided, enough is enough, then I’d imagine the game would revert to just offline use. MS would shut down the servers, freeze the sim in its current state, and then you fly with generic autogen, like people do in X-Plane. No more reporting home to mother for the sim, no more group flying. We’d be back to offline mode, with addon scenery.