So when eden comes back, does that maybe mean they're coming back down here, and maybe heaven goes back into the tool box?
Heaven was never in the tool box. Originally, God designed humans to live forever on earth. Just because we are mortals didn't mean we had to die....it just meant that we could lose our lives if we disobeyed God.
The only mention of death in the garden was as a penalty for disobedience. Since the Bible does not mention a "heaven or hell" scenario, those who die, sleep in death. The "righteous and the unrighteous" will be resurrected from their graves (John 5:28-29) but the wicked will not have their lives restored. There is no heaven or hell....there is just life or death.
Look what God said after Adam had taken the fruit to join his wife in rebellion....
Genesis 3:22-24...
"Then the Lord God said, “Behold, the man has become like one of Us, knowing good and evil; and now, he might stretch out his hand, and take also from the tree of life, and eat, and live forever”— 23 therefore the Lord God sent him out from the garden of Eden, to cultivate the ground from which he was taken. 24 So He drove the man out; and at the east of the garden of Eden He stationed the cherubim and the flaming sword which turned every direction to guard the way to the tree of life." (NASB)
There was another tree in the garden that was freely available to the humans.....one that would make them "live forever"....there was no prohibition on that tree, only on the "tree of the knowledge of good and evil".
But when Adam and his wife ate the forbidden fruit, God immediately withdrew access to "the tree of life", thereby allowing the sentence of death to be carried out. But before they died, God allowed them to fulfill his original mandate to "fill the earth". The lesson that he would allow, was to be learned by all of humankind before he restored his rulership to the earth.
So you see, there was never a reason to go to heaven.....everything that people think heaven is, was right here on earth. What Adam lost for his children, Jesus came to 'buy' back for them. That is what a redeemer does.