Okay so it actually seem to be true. Thanks to @idknametoget, we continued this conversation on private messages and I was able to adjust and enable the FFlags on the Microsoft Store version of Roblox.
This dialog appears when the phase 1 flag is enabled:-
And this appear when phase 2 flag is enabled:-
Interestingly enough, the Microsoft Store app is currently two versions old, so it might be a sign that this will happen soon. I’ve updated it to the latest version and the latest version for it is release 670, while the latest version for all other platforms is release 672. Add to that that the Microsoft Store app haven’t been updated with the new icon too. I wonder when will this happen and if it will happen really soon…