Haha! Not an urban myth 
. Call Laminar and they’ll tell you themselves. Maybe even the FAA can put in a word. There is a special FAA version of X-Plane. To get it FAA-certified, Laminar Research has provided a special version of X-Plane that can be used in combination with simulator hardware that is FAA-approved. Because X-Plane is designed to be compatible with that hardware, it is therefore FAA certified.
The difference between a retail video game and a professional simulator, is that a professional simulator is meant to cost thousands.
The moment Microsoft/Asobo apply for FAA-certification and obtain it, then we can call MSFS a simulator. Till then, it’s just a video game.