Incorrect. You cannot do this in native xF. xF sees users who have registered but have not received the confirmation email or have not confirned, the same as an unregistered visitor. So that xF sites who don't allow visitors to use the contact form, also block these registered usrrs.
If you have the "Unregistered/Unconfirmed" group set to disallow the contact form, there is no need for this add-on.
Always been there as far as I know.