Well, I’m not positive how helpful that is in the present discussion. because He wasn’t telling the apostles to “Bite Him” either.
Most messages to the apostles, those which did not impinge upon their apostolic duty, were also intended for Christendom in general.
But I can see your point, if we take the blood/flesh literally why not take the apostolic address literally too.
Why not take John 6:63 literally, then, where Jesus said that the Spirit gives life, the flesh is no help at all?
Or when Jesus said that He was the door, or the true vine.
I don’t suppose that Catholics would consider Him to be made out of wood or green and leafy.
To think that Jesus would command His followers to break the Law by consuming blood is ludicrous.