This is a breaking change to anyone who used glsl/hlsl.saturate functions prior, but the y and z parameters never were used and do not conform to how the saturate function works in HLSL: https://docs.microsoft.com/en-us/windows/win32/direct3dhlsl/dx-graphics-hlsl-saturate
Note however GLSL does not contain a saturate function, but removing it does not accomplish anything good IMO.