Intellectual property does not die with the person who owns the intellectual property.
That’s why you could not go out and legally sell Elvis Presley albums, but his heir can sell Elvis albums and make money.
That's why our system is screwed up; the Constitution says To promote the Progress of Science and useful Arts, by securing for limited Times to Authors and Inventors the exclusive Right to their respective Writings and Discoveries;
where we now have, effectively, an unlimited time span. (And yes, I do blame Disney and the Supreme Court.)