Maybe the idea of the new book was to point out that you can read LotR and Silmarillion as myths and histories written in-universe, instead of an objective and

Maybe the idea of the new book was to point out that you can read LotR and Silmarillion as myths and histories written in-universe, instead of an objective and reliable narrative. Suddenly all sorts of things might be slanted to make the winners of the war look good and noble and paint those who opposed them as beastly savages.