This is an excellent point that many others don’t think about.
If other sims announced that they were closing today, we’d still have years upon years in sim time because all of the downloaded content we have. However, if MSFS pulled the plug I am pretty sure the sim wouldn’t be possible to play, based off of all it’s online streaming data.
That being said, Microsoft is a huge company and they’ve said over and over that they’re in it for the long haul.