There is nothing in that particular discourse that sets it apart from the rest of the scripture. All of it is given us for reproof and faith formation, as St. Paul says in 2 Timothy 3. This particular passage is there for us to know that the Eucharist is not a metaphore but rather is "food indeed": something we physically eat while it really is Jesus' body.
John 6:63 explains the nature of the Eucharist further. It does not negate the preceding discourse. It explains that while His flesh Jesus will give us is "food indeed", it is not there to feed our flesh, that is, our stomach, but rather to feed our spirit. It therefore is the refutation of the charge of cannibalism that opens up the discourse.
John 6 explains that we are to eat His flesh and drink His blood really - not literally, not figuratively - but really.
So then.. you don't "like" metaphors and believe them to contain not MORE information bur LESS.. That metaphors are not a richer more detailed example of discourse but an example of unnecessary information?.. And Jesus who used metaphor almost exclusively.. was not very clear in his speaking.. You know; GOD, that has a public speaking problem..
One wonders what "other" of Jesus spiritual metaphors have you missed... and counted them literal..