When installing "Minecraft for Windows" through the launcher,
the button on the "Minecraft: Java Edition" page displays "Waiting for installation"
and the "Minecraft: Java Edition" game cannot be launched.
Steps to reproduce the problem:
Turn on a Windows 10 computer that does not have "Minecraft for Windows" installed.
Click "Install Game" on the "Minecraft for Windows" page of the launcher.
Go back to the "Minecraft: Java Edition" page and find that the button changes to "Waiting for installation", at this point you cannot start the game, and need to wait for the "Minecraft for Windows" installation to complete.
(My launcher version may not be up-to-date (Windows 10.0 2.12.17), but my Microsoft Store tells me that there is no updated version, and the launcher was installed on November 3, and I don't know of any way to force an update)
This is not a bug and expected behavior. I'll resolve this as a duplicate of MCL-21862.