"F*** off! That's a waste of time, and the whole team knows it. My job is to have this team excel and make a ****-load of $$ for the company, and to develop my subordinates so they can make more $$ and develop their own careers and CVs, end of ****ing story."
It seems poor Bradley is a bit confused about their role. The first bit is accurate, but the second is misguided.
Nevertheless, management should try working with Bradley to see why people are leaving. It's possible that people could try to be retained. See what Bradley's thoughts are on the problem of people leaving.
They may think it isn't a problem. In which case, you all need to come to alignment before you proceed.
Upper management trying to shoehorn random solutions into Bradley's way of managing is not going to end well if Bradley isn't on board with what is being attempted.