I don't think there's much to say about this, except that it seems like a case of J.K. Rowling trying to retroactively bestow a level of adult complexity on her characters that they don't possess on the printed page. A writer confident in her powers wouldn't feel the need to announce details like this after the fact, and a writer who understood the strengths and limitations of her creation would recognize that trying to smuggle this level of psychological realism into the Potter series is a fool's errand that can only diminish her achievement - by reminding adult readers of what it isn't (a serious work of realistic fiction, I mean), rather than letting them enjoy it for the gripping, inventive children's fantasy it is.

Update: My response to Neil Gaiman's remarks is here.