In many ways, Modern Family is Jay's story, showing how an old fashioned guy who already raised kids to adulthood would navigate a new, "modern" world with a younger wife (Sofia Vergara) and stepson (Rico Rodriguez). Jay's death would complete his arc, and possibly give significance to the doc-style "talking heads" interviews Modern Family is famous for. Maybe the family is watching a movie they made about their dad's life, only deciding it is finally time to finish it after his death.