Nope, he hasn't learned a thing. The original Dimbleby interview was 2.5 hours long, but all anybody remembers is the few minutes during which he admitted his relationship with Camilla.

Charles supposedly wants Harry at the coronation because, if he doesn't attend, the media will focus on Harry's absence. Yet it doesn't occur to him that if he tries rebut Harry's claims during an interview which is being pitched as being about his life and his plans as monarch, that the media will only focus on what he says about Harry?