That is pretty much how they worked the Posix compliance requirement for government/forces use for NT/2000: the API was available through an optional (and IIRC not quite complete) module that very few ever turned on even where it was a contractual requirement that it be present.
The option you suggest could be present but no doubt not be in use by many people because extension-X, third-party-app-Y, or internal-automation-subsystem-Z, or some feature of AD itself, would break.
That is pretty much how they worked the Posix compliance requirement for government/forces use for NT/2000: the API was available through an optional (and IIRC not quite complete) module that very few ever turned on even where it was a contractual requirement that it be present.
The option you suggest could be present but no doubt not be in use by many people because extension-X, third-party-app-Y, or internal-automation-subsystem-Z, or some feature of AD itself, would break.