Thoughts
1: If Luke is correct in his timing (very early in the ministry of Jesus) then it is no wonder that Jesus does not mention anything but debt and forgiveness.
If Mark and Matthew are correct in their timing (only two days before Passover) then indeed Jesus may have referred to his death. But then why would Mary have prepared and brought spices to the tomb if Jesus had already been anointed before his burial?
If John is correct on his timing (six days before Passover), then this is too early in the week for Jesus to be anointed for his burial. But Jesus must be anointed before he is proclaimed as king during his entry into Jerusalem.
DAB