ENH: Should  `pandas.CategoricalDtype` use `pandas.NA` as the sentinel value instead of `float('nan')` ?
Almost all of the the new nullable data types (which are incredibly useful btw.) seem to use `pd.NA` as the null-value.
However, I noticed that `pandas.CategoricalDtype` still uses `float('nan')`, which I suppose is for historical reasons.

Are there any plans - for the sake of consistency - to switch `CategoricalDtype`'s sentinel value to `pandas.NA` in the future?