Ever notice the one book-on-tape Tony brings her is "Omerta?"

Looking back, Season 2 had its finale in April 2000, and Nancy Marchand died in June. Had she not passed away, Livia potentially testifying against Tony was to be a central plot line in Season 3, so not only did David Chase have to massively change course, he had to tie her death in as well. Perhaps that scene was an attempt to try something different from other instances where a major character died unexpectedly.