'az aro delete' not deleting created app registration

When creating a cluster using 'az aro create', there is a resource group of the form 'aro-xxxxxxxx' created. It appears that along with that resource group, there is an app registration (service principal?) created with the same name in Azure AD. However, when doing an 'az aro delete', while it deletes the OpenShift cluster object, it does not clean up the associated app registration.

Ideally the 'az aro delete' would remove all items it created. Otherwise the it'll be left to the end user to clean up these items manually.