Obviously they do not publish an obituary in the ships news. Its kept quiet out of respect for the passengers family and also so as not to unnecessarily alarm the passengers who might wonder what the cause of death was. Several different sources have corroborated this. Each cruise ship routinely stores coffins for human remains among its supplies.
You really think someone could die on a cruise and the news would not leak out...come on man! People definitely die on cruises...but its not any where near a normal occurrence!!