Actually as far as restricted goes, that should be desired. Just because a person is an oper doesn't mean they have the right to be allowed in a channel the founder clearly wants to be restricted. IRCops or even admins are not all powerful, can go anywhere, do anything users ye know.
Additionally opers don't need to hang out in forbidden channels, afterall FORBID means the channel can't be used, so stay out. There are other ways to keep users out of oper only channels. for example setting restricted on.