As described in
QTBUG-62439, QTBUG-70287 will move towards a single shader language in Qt Quick and the related 3D offering, whatever it may be. In addition, shader graphs should be explored, with the intent of enabling visual creation and editing the shaders and materials.
This will likely not be feasible for Qt 6.0 due to time constraints, and also due to dependencies on other work to be done for 6.0. Rather, it may be a better approach to target a later 6.x release with this, after the approach to handling shaders is finalized in 6.0