ordinarily I would agree - but as we have seen from Chris Roberts - you CAN still get in front of a camera or make a personal statement about how "your baby" is developing IF you have the desire for it.
I very much doubt that all of his time is taken up as we might think - as you say - delegation being a viable option to free yourself for more time to do certain activities, plenty of world famous CEO's have done this - Bill Gates and Steve Job's to name just two of the most prominent - and both of those had one major thing in common, they had the deep desire to "get into the nuts and bolts of a project" - it was how they started out and that desire normally never dies.
As I said in my post about passion - if you truly want to pursue it, or devote more time to talking and promoting something, you'll find a way. Desire for something is hard to supress or hide from view- a lack of desire equally so.
I'm not saying he's given up as I have no knowledge either way, but apart from extremely rare occasions - usually promotions with the world watching, DB is pretty quiet about a lot of things regarding ED, when there is still much to discuss.