Church history and Evangelical Protestantism

No, your insistence that Christ was actually referring ahead to the literal "food" of a communion meal is based on your particular presuppositions. This is just like when a woman asks him about water, and he speaks of living waters. Is this pointing forward to some water being His body, or perhaps the sweat or water that came out on the Cross? Or is it the Holy Spirit that is literal water? Or perhaps a "real presence" in the waters of baptism? I have never heard either Catholics or Campbellists claim that one, (maybe I shouldn't give y'all any more ideas!:laugh So Christ draws these analogies with real food, when someone mentions it.
The communion meal points back to Christ's metaphor of eating His flesh, and His literal flesh being "broken" for us on the Cross. You have it the other way around, where the physical bread is the "real deal" Christ points forward to, but there is even less scriptural justification from that. Premise is being stacked upon premise.

Yes, later. He was not talking about the same thing in both instances. The later reference was called direcly by Him a "remembrance", not the real deal He was speaking of all along.

But it is not taught in the texts, and is not clear. (else, it wouldn't be an "oral tradition", would it?) You project it there, not me; so that is what is "novel" regardless of it's "ancientness", and you define "realistically" as physical items having some sort of supernatural presence, rather than the original context of His death being the "breaking" of His flesh, and our believing in Him being "partaking" of it, with Him being spiritually in us.

It's a remembrance. As we partake of the elements, it is a reminder of what He has done for us, almost like a new giving of it, but not, because ot was a once for all act.

Again, you misunderstand His whole parabolic style; just like the living water that would be given to us, so He is giving us living water (eternal life through the Spirit), and He is giving us His flesh (salvation through pardoning of sins when we believe). The two work together, covering the same thing. Your "plain grammatical meaning" is a red herring, because prarables and metaphors are often spoken in a literal fashion. What Christ goes on to say in that passage is "The flesh profits lnothing; the words that I speak, they are spirit and life". Those people, with fleshy thinking, took it too literal, and Christ is here telling us it is spiritual. But you are making it some literal thing again, and only use "spirituality" to explain the resulting dilemma of why "it doesn't like like flesh".