I often wonder what universities brings to students who are already performing in professional life. I’m tempted to ask “So what is he going to teach?” to such stories.
Networking, physical and information resources, help with learning things he might have had trouble grokking, and the signal provided by a degree to get into organizations or events that might not have heard of him. If a very smart and already accomplished person doesn't worry about money, academia (at least attendance) can be a very good choice.