You are contradicted by verse 17 where it clearly said "For behold, I create new heavens and a new earth".... So that passage is not talking about the millennial reign (which will also be peaceful) it is talking about the New Earth.
But that's not just my take on it, pretty much all the commentaries and Bible teachers that I've read in regard to that passage state that it is about the New Earth.
You also ignored that God made covenants with the animals too, not just humans, with the promise of a future peaceful world.
And you're also contradicting yourself when you say that the earth will return to the original Eden world, but without animals. There were animals in Eden, and as Genesis 1:29-30 clearly states, they were created as herbivores. Do you really think a God of love and peace wants humans and animals to be at each other's throats in a constant bloodbath just because of selfishness? I mean, do you REALLY believe that?