These stories show what should have come as a logical surmise even without them: if someone was buried in a tomb and later the body was not there, this fact alone would not make anyone suspect that God had raised the person from the dead. Suppose you place a corpse in a rock-hewn tomb. Later the body is missing. What is your immediate thought? It is definitely not “resurrection.” Instead, it is “grave robbers!” Or, “someone has moved the body.” Or, “hey, I must have come to the wrong tomb.” Or something else. You do not think, “Oh my! This person has been exalted to the right hand of God!”
