This would providing cleaner CMake API inside the Qt CMake files.
For example for qml, without this feature, you could have a hypothetical API as follows.
qml_run_quick_compiler needs to be called manually by a user after all qml_target_sources have been called.
With proposed feature, we could have a cleaner API where the user does not have to specify the qml_run_quick_compiler call, it would be called automatically by CMake.
and inside add_qml_module you would have something like:
Thus the user can't accidentally forget to call qml_run_quick_compiler(), CMake would do it for them.
Upstream issue https://gitlab.kitware.com/cmake/cmake/issues/19575