the author could be alive, and write new works, and that seems more likely

any member of the family could also contribute to society by writing new works

remember the goal: to promote new works; not to make the author money, or their family money, or their family's descendants money; and not to enrich or prevent the enriching of any given publisher

allowing the author and family to milk old work in perpetuity, whether independently or through a publisher, would seem to incentivize the opposite of that