Mark, the earliest Gospel, ends at 16:8 with no appearance stories. Doesn’t that mean the appearances were invented later?

Mark’s original ending does stop at 16:8, and most scholars agree that verses 9 to 20 were added later. But Mark is not silent about appearances. The young man at the tomb announces that Jesus is risen and tells the women he will be seen in Galilee (16:6 to 7), so the account presupposes appearances rather than lacking the idea. And Paul’s list of appearances in 1 Corinthians 15, which he says he received from others, was written before Mark, so the appearance tradition is older than the earliest Gospel, not younger.