I don't think he is trying to control what the media says about GT. I think he is trying to control the culture of the team. If he tells the team to concentrate only on what they are doing right now, but is on the media talking about extraneous things, it looks hypocritical. When they are practicing, he wants a LB to learn what his responsibility on a certain call is. He wants that LB to know what to do in reaction to what the offense does. He wants that LB to know that without having to think about it. He doesn't want the LB to think about BG from last year and how disappointed everyone will be if we lose to GA State, instead of concentrating on what he has to do himself. I think he doesn't want to talk about it because he doesn't want such thoughts to trickle down to the players and change how they practice and perform.
I think Quinlan said on a Youtube live stream that Key had asked several reporters for feedback about his performance at press conferences in the last couple of years. Key strikes me as a detail oriented and method driven person. It appears that he is listing out his roles: Coach, mentor, PR guy, recruiter, etc. Then he is working on each of those to find out what he is doing well for that activity, and improve what he is not doing well at for that activity.