Although the game will be available for Xbox Game Pass on PC as early as August 18th, you will not be able to play Microsoft Flight Simulator 2020 on Xbox One.
This is because there is no release date for the ambitious pilot-sim on console yet despite a version being in the works.
In regard to the Xbox One version, no release date has been announced, but developer Asobo Studio have said that it will not jeopardise the PC version.
“The Xbox will help us to optimize the product, so it will also be a benefit for PC,” said lead software engineer, Martial Bossard.
https://www.hitc.com/en-gb/2020/08/17/will-microsoft-flight-simulator-be-on-xbox/