The default Staff group that comes with Discourse is for all Admins and Moderators. To be in that group (and in fact to see that menu item at all, come to think of it) the user must be at least a moderator so no, the function can’t be turned off.
No, it doesn’t send a notification but TBH I’ve never heard of this happening before so I suspect you may be trying to fix something globally for a one off issue that is reasonably easily rectified.