True story -- I got hired at a startup, and sometime within my first few days we went into a team meeting. The Chief Product Officer plugs his computer in to present, and Slack is up, showing his direct conversation with HR regarding my salary. Team lead saw that I had been brought on for more than him and quit. Many others threatened to quit, and they had to give a lot of raises. I guess it wasn't a notification but easily could have been.

I don't live a life that will put me in a position to be embarrassed by notifications (at least not like on the site), but there is nevertheless a real business need for privacy that is not related to what some might call immoral behavior. I think to expand the reach of this product you might need to take that angle. If Muzzle is meant only to handle embarrassing notifications, I believe it will become embarrassing to have it/be using it. Just my 2 cents.