logic is implemented to ensure that email notifications are only triggered when both the 'Authenticated user' role is selected in the allowed roles configuration and the 'Trigger email if users have the 'Authenticated user' as their only role' checkbox is checked. checks are present to prevent notifications from being sent if the 'Authenticated user' role is unchecked, even if the checkbox was previously selected. Tested various scenarios to confirm expected behaviour.
So moving it to RTBC.