I believe this is the theory. But Asobo/Microsoft “switched off” the frame rate limiting in MSFS 2020. Somebody wrote a long post why this is beneficial for us PC users, see V1.13.16.0 - screen tearing not a bug but a design change - Community / General Discussion - Microsoft Flight Simulator Forums
I think Asobo/Microsoft changed this detail of the graphics pipeline because Xbox OS does not support it.
Out of the blue I say: Xbox OS is a subset of MS-Windows OS.