Revelation 21 shows the New Jerusalem coming down out of heaven prepared as a bride for her husband to the new heaven and new earth (vv. 1-2). This is referring to AD 70, the time of God’s marriage to His people at the destruction of harlot Jerusalem…

This is unsubstantiated and depends on the assumption that Revelation 18-19 speaks of judgment on Jerusalem rather than Rome. That cannot be addressed in detail here, but I pointed out in The Coming of the Son of Man that the visions of seven bowls all draw on Old Testament texts that speak of judgment on the pagan enemy of the people of God. To be honest, I really don’t understand how people reach the conclusion that ‘Babylon the great’ is a symbol of Jerusalem rather than of the current pagan oppressor of the people of God. Why shouldn’t John have foreseen judgment on Rome as well as on Jerusalem, fully in keeping with the pattern of Old Testament prophecy?

Thus, the new heaven and new earth do not happen after the millennium, they are concurrent with it.

That just defies the narrative logic of these chapters for no good reason. During the 1000 years evil and death are still present; satan has not been destroyed. In the new heavens and new earth, these destructive and corrupting forces have been finally eradicated.

The events associated with the coming of the Son of man (ie. the concrete historical vindication of the people of God through the destruction of Jerusalem and the victory over paganism) culminate in the awarding of a kingdom, first to Jesus, then to those who suffered with him. This is where we are in Revelation 19:16 - before the 1000 years. Nothing is said about kingdom in Revelation 20:11-21. The regeneration of the people of God following judgment requires a king because there are still enemies. In the new creation there are no enemies left, no more battles to fight, therefore no king is needed.

It seems to me that what has happened with the new creation theme in scripture is something like this:

1. It begins with Abraham, who is called to be God’s new creation (‘I will bless you; you will be fruitful; I will multiply you; and you will fill the land’).

2. The restoration of Israel is depicted in Isaiah 65:17 as a renewal of creation; the old world of judgment passes away, a new world of rejoicing is inaugurated.

3. This theme reaches a climax in the New Testament, as you point out: the ‘regeneration’ of Israel is again thought of as a renewal of heaven and earth.

4. However, at this point something new is introduced. The resurrection of Jesus takes us beyond metaphor to a real victory over death. It is this unexpected development that raises the possibility that eventually a creation that is subject to decay will be radically transformed - to the extent that corruption, sickness, evil and death have been eradicated.

5. This bigger vision is clearest in Romans 8, where creation sees in the glorification of the sons of God (ie. the suffering church) the potential for its own liberation from the bondage to decay; and in Revelation 20-21, where the victory of the suffering church over Rome is separated from the final judgment and renewal of creation by the 1000 years.

One final observation relevant to this discussion:

Notice that inside the “city” are the redeemed (Rev. 21:24-27), while outside it are the unredeemed…

This is misleading. I think that at Revelation 22:6 we revert to a pre-parousia situation - John voices the hope that Jesus will come soon (22:7). This is not part of the new heavens and new earth image - notice that the wicked who are outside the city in 22:15 are thrown into the lake of fire following judgment in the new creation (21:8). What 22:14 describes is the entry of the martyrs into the city and the exclusion of the wicked from it. They are then kept in the city, where they reign with Christ, throughout the 1000 years until the city descends to be part of a pristine new creation.