Legacies, especially what constitutes them and who has access to them, have changed a great deal over time. For instance, Willa Cather, a giant of 20th century American literature, and author of classics like "O Pioneers!" expressly forbade the publication of her personal correspondence. Her wish has largely been respected and enforced by her executors since her death seven decades ago.
http://www.thetakeaway.org/story/278179-managing-our-digital-legacies/