Careful with that legal “assessment”.
At least in case of the Steam version all you do is purchase “credits” for the Microsoft Flight Simulator. That’s what the statement says that I get from Steam: “Microsoft Flight Simulator - 032 Credits”. I have no idea how it works with the non-Steam versions.
Even though I don’t like that I don’t get an email from Microsoft saying “thanks for purchasing XYZ on the Marketplace” my monetary transaction is with Steam and they send a receipt containing that not very helpful information about the credits. I’m not a lawyer but I guess that’s not breaking any of our laws here in Germany.