The argument there is that avogadro's constant is just an arbitrary number and mol is not an unit, but weird case of SI prefix. On the other hand it is fundame

The argument there is that avogadro's constant is just an arbitrary number and mol is not an unit, but weird case of SI prefix. On the other hand it is fundamental-ish constant, because it is defined as arbitrarily scaled result of inherently uncertain measurement. And the new definition of kilogram had significantly increased the attainable certainity of such measurement (to the extent that it is uncertain due to practical issues, not by definition). The other proposed replicable definition of kilogram (ie. mass of Si monocrystal wih particular geometry) would fix the definition of mole as some known and defined number, but would be significantly harder to replicate (because it would define how to produce an artifact in contrast to how to directly measure the mass as the ratified definition does)