Why Named barrier new OpenCL 2.1 extension is remove in final version!

seeing final OpenCL 2.1 extensions document vs the provisional one I see two new extensions are removed:
*Named barriers for subgroups
*Subgroup Independent Forward Progress
can at least say why they have been removed?
they exposed advanced functionality exposed in CUDA also which some optimized libraries are during this adv functionality like http://legion.stanford.edu/pdfs/singe2014.pdf
also seeing AMD today announced effort to support CUDA (HIP) this functionality would be good also…

As posted here:

Sub-group independent forward progress has been moved into the core specification. You can check whether a device supports this feature by using the CL_DEVICE_SUB_GROUP_INDEPENDENT _FORWARD_PROGRESS query.

The named barriers extension was targeting the provisional OpenCL C++ kernel language. Since the OpenCL C++ kernel language is still under development, it didn’t make sense to include this extension in this version of the OpenCL 2.1 extension specification.