The Diana debate will never die down because she is an historic personage,and a divisive one, during her lifetime and following her death. Exactly as has happened to Anne Boleyn, Mary, Queen of Scots, Marie Antoinette, Empress Elizabeth of Austria and Tsarina Alexandra, to name but a few.
As time passes more verifiable evidence will become available, from state papers to personal, private recollections and although recollections may vary serious books will be written that attempt to examine all the existing evidence and draw balanced conclusions. But not until after Harry's death, I would think, as he does have an understandably skewed view of his mother, developed after her tragic death and
exploited recently by his wife.