The professional thing to do would be to keep the discussion internal so that all parties involved could get the information in a similar timeframe. Leaking it like this puts undue pressure on Board members and, depending on how maleable that person is, can bias their decision. It's also a bit of a farce that Mack (regardless of how you feel about him) has to hear about his impending demise through a gossip column.
People like to complain about professionalism (whether it's a coach, a player or other parts of the organization) .. this is yet another example where the Board falls short .. do you think True North would air their dirty laundry in the media? Likely not.