Well, first, I have to say that it was delivered in a parenthetical and disjointed style that made it horribly hard for me to concentrate on what he was saying; however, I did make it to the end of the video.
A few thoughts on the topic:
Funerals are for the living, not the dead. They are to help those alive deal with the loss of those who have died. A phrase the comes up in every Jewish worship service that includes the Mourner's Kaddish (prayer for the dead) that I have attended is "May the Source of peace bring peace to all who mourn, and comfort to the bereaved among us." Notice that this is aimed at those left behind - not at those who are dead.
The concept of an afterlife exists in many cultures, in a variety of fashions. If you grow up in a culture that includes an afterlife, then to decide you do not believe in an afterlife requires you to consciously reject that belief - and even so, for many people, a niggling doubt remains, due to a need to plan for all possibilities, along with the difficulty of completely rooting out childhood training.
For myself, I have a problem with the idea that all life as we know it is a proving ground that leads to eternal punishment or salvation - if only because of the number of people who have tried to convert me with based on the idea that, as a Jew, I am damned to Hell no matter how I live my life, or console me with the idea that I am condemned to Limbo, that I can access only the very outer reaches of Heaven, or (my personal favorite), that I will spend the afterlife in a type of "college" where I will have until Judgment Day to change my mind about my beliefs so I can be saved, lest I spend the remaining portion of Eternity in Hell.
To return more directly to the concept of atheism as a consolation - all I can say is that everyone is different, everyone responds to grief differently, and if the concept described works for you, great! That does not mean to me, however, that it is appropriate to tell anyone who believes in an afterlife and takes comfort from that belief that such belief is wrong - especially immediately following the loss of a loved one.
When I was about 10, a great-uncle of mine (whom I had never met) died of age in his upper 90s, quietly, in his sleep, without any protracted illness or disability. The rabbi who conducted the funeral service included an idea that has stayed with me to this day, some 30 years later: we should not grieve for this relative, who died peacefully at the end of a long, productive life - rather, we should consider that life is like a journey in a sail boat, that his life was the journey from port, through the storms, shoals, and calms of his life, and that he had, now, returned peacefully to dock. Others would no doubt find this as useless as Penn's friend found his message about his mother's death.