Bing maps is being updated all the time. As Bing maps is updated then FS can be updated too.
Not only that, they are not only using satellite imagery, they are literally sending up airplanes to scan/take photos of areas they want to improve. I got this information last week from some source I can't remember, but that's how they do it (as do Google actually), and from what I understand (don't quote me..) Flight Simulator is one of the reasons they have upped the frequencies of these map update photo-shoot flights lately. Perhaps that's where some of the world updates stems from, IDK.
Traditionally Google has been the best at photogrammetry (f.ex. in Google maps my area has great photogrammetry, in MSFS there's NONE, only autogen
((( ..), and some Google Earth cities where both have photogrammetry unfortunately it looks considerably better in Google than in MSFS/Bing, but let's hope Bing can somehow manage to surpass them soon. I guess Google has the advantage in being able to fuse their huge pile of data via satellite, airplane and street imagery.
Oh, did you know that you can import Google Maps scenery even photogrammetry into MSFS..? You can actually do it by yourself by using the built-in SDK. I haven't tried it yet, don't even know if I'll bother anytime soon, but the option is there.