It’s a freeze frame, a snapshot in the family photo album. Everyone is listed by tribe, who was there in Jerusalem at the completion of the walls, when Jerusalem is again God’s city, for the Jews with its own identity defined by walls to keep it strong.
It sets the scene for 8 where Ezra will read the law, an act of rededication.
Problem is that life goes on. There is precious little in the wonderful task-oriented focus and clarity of Nehemiah (so far at least) to talk about the eventual fall of the physical Jerusalem, once again, and the future destruction of the temple.
Let alone the glorious doctrine of the temple of God being each believers body, or the eternal new Jerusalem, built by the blood of the lamb who is god made flesh and populated by people of all nations.
The last book I read was Daniel. It was shot through with all that. He was always in a state of deep disturbance about his apocalyptic visions. He experienced the saving power dramatically and concretely, but it came with visions that said all the here and now is ultimately to be overwritten by much larger plans of God, part if which will involve hardship.
Still for the people who were there on the auspicious day of the completion of the wall, they got the joy of knowing they had done god’s will, completed his unambiguous mission here on earth. It happens sometimes, and it is to be enjoyed.