To answer the real question. If you die on board, you are body bagged, placed in one of the six containers (coffins) the ships carry as standard. Placed in a fridge beside the vegetables etc and shipped off at the first available port with an airport.
People will be on hand to help the people you left behind and ship you and them back home by plane. But that will all be covered by your personal insurance or cost and not the lines, so be aware