It could be that they are trying to release this change with improvements to lighting shadows as a whole, because right now they have a few issues:
- Objects leave a light outline around the cast shadow
- Inaccurate shadows when the shadow is cast onto a non-CastShadow object
- Shadows Are Completely Incorrect For Layered Clothing - #13 by Judgy_Oreo
A lot of these seem to be caused by Roblox’s implementation of shadows, AKA how the engineers coded them. It could take a while to change implementations to one that does not have these issues.