At the moment, the Client Review Site creates 'Client Notes' that can be hidden from certain permission groups by the permission "Can Lock Playlists and Share Playlists via Client Review Site", eg:
However, there's currently no easy way to transform a hidden Client Note into a Note visible to all permission groups, aside from copying the Note and pasting into a new Note.
Please add your support to this feature request if you'd like to be able to easily transform a Client Note into a normal Note visible to all permission groups.