With FHIR-28593, the definition and value set of a MedicationUsage status have changed.

Before that change, the status field was related to the medication, and it is now related to the statement (record).

Still, the statusReason (example) binding didn't change, and remained related to the drug / medication, which is not consistent with the new status scope.

Even if a MedicationUsage statement was "entered-in-error", we may not need a statusReason anymore.

Removing this field would prevent misusing it when migrating from a previous version of FHIR.

If you think the statusReason field should be kept, then its value set should be changed to contain other example codes (although it's shared with NutritionIntake... which is also strange).