Really? No post resurrection accounts?
Been thinking about this. Agreed, the appearance of Jesus after his death was essential for the disciples to believe, since seeing is believing. This is why Mark's epilogue is a perfect ending.
Without the epilogue, Mark hasn't said anything about how the disciples came to believe in the resurrection. Yet we know Mark himself believes in it, otherwise why did he tell us about the young man's message? If he intended to end at 16:8, perhaps he is asking us to trust the message of the angel, since we do not have the experience the disciples had that led them to believe.
Looking at the trial/crucifixion/burial narrative in Mark and Matthew they are almost identical except in the sections Mark omits (or Matthew adds) - Judas' suicide and the guards at the tomb. But if we had to decide whether Matthew added or Mark omitted Judas' suicide, I would say it would make more sense that Mark omitted it, given its natural positioning in Matthew between verses 2 and 11 of Mt 27, between the trials before the Sanhedrin and Pilate.
Matthew and Mark both contain details about the rendezvous in Galilee, Matthew the complete story and Mark only up to the angel's message. We could ask: if Matthew has the complete story, why does Mark only have half of it? To me it reads as though Mark is aware of the actual rendezvous in Galilee, even though he doesn't tell us about it. If Mark was third (and if the epilogue was his own work), maybe he was faced with the two different accounts of resurrection appearances in Mt and Lk, and decided to use both of them, hence he omits Mt's record of the Galilee rendezvous (having recorded the promise of it) and instead gives Luke's three appearances.
In a way, this is what we would expect ot find if Mark was conflating two different narratives. We would see signs of discontinuity at the points where he switches from one source to the other.