Increase, sure. Is that due to society changing or the Rooney Rule? I'd frankly be amazed if there was any change due to it.
No rule was needed for Black QBs to have significant number in NFL.
Sport management isn't like normal work. It's not like a chairman puts a job advert out there is it? In almost all cases, chairman has a preferred choice of manager they want. Unless that person pulls out, they get the gig - any interviews merely to conform with the rule which certainly in America is no longer needed.