In a (much more rational than SI) system "h=c=1" there is only one fundamental unit left - kg (or ev, which still depend on a kg definition). So getting rid of kilogram is absolutely essential.
That system is mostly irrelevant for cultural and legal purposes. Even in the specific philosophical framework where getting rid of the kilogram 'absolutely essential', the current importance of the kilogram would simply migrate to the importance of the specific conversion factor to traditional units.
