What happens to an author's papers after they die isn't always what they intended:
Three years before his death, Ernest Hemingway placed a letter in his library safe stating, “It is my wish that none of the letters written by me during my lifetime should be published.” Yet by 1976, his widow, Mary Welsh Hemingway, was already quoting those letters in her memoir, How It Was. In 1981, only two decades after her husband’s violent suicide, she allowed the publication of six hundred letters in Ernest Hemingway: Selected Letters, 1917–1961.
And, in 1999, Hemingway's son published a "bowdlerized version" of True at First Light, the author’s last unfinished work. To combat the problem this exemplifies, some archives are moving to acquire literary estates while the writer is still alive.