When Harper Lee, the author of To Kill a Mockingbird, died in 2016, there was considerable publicity as writers attempted to uncover all the details of her life. They met with little success. Lee’s will has been unsealed but it does not reveal very much either, according to Al.com in "Harper Lee's will is unsealed but questions about the legend of American literature remain."
Lee's will directs that all of her assets, including literary property, be put into a previously created trust. Details about the trust are not publicly known. There does not appear to be a way to make them public. The trust's beneficiaries and trustee are not known.
What Lee created is known as a pour-over will. It is a simple way to have assets transferred to a trust, after someone passes away. Since trusts do not have to go through probate and are private, this is a great method to use for people who do not want the details of their estates known to the public, as Lee apparently did not.
An estate planning attorney can advise you in creating an estate plan that meets your specific privacy needs.
Reference: Al.com (Feb. 27, 2018) "Harper Lee's will is unsealed but questions about the legend of American literature remain."