I've posted several times we should have a contact person to email (if an inquiry is appropriate) in our personal info specs. Keep it voluntary. Either that or ask family to notify an SI friend if anything happens and ask them to post.
I have a book a friend bought me a while back, “I’m Dead, Now What?” It has sections to list assets, estate planning documents, along with other info about last wishes and people to contact upon one’s demise. Having done a fair share of probate work, I know such information would be useful to friends and family.