It seems to me that the purpose of the people taking time to overview their history was two- fold. The passage speaks of exalting God in verses 5 and 6. It brings attention to the attributes of God as promise keeper (vs 8), covenant keeper (vs. 32), as just and faithful (vs 11,12,13,15,20,21, 24, 33), as compassionate and kind (vs 9,17,19). All this to bring God glory. There also seems to be an element that is for the purpose of acknowledging their sin and repenting of it.
I have never read Nehemiah 9 as a two-fold part of history, but now that you have said this it makes sense to me and changes the way I read that passage. Through all of Gods attributes listed, it reminds us that He is willing to save us from our sin and that through it all He will always be there for us when we need Him.
This is a refreshing new perspective on Nehemiah 9. I love how you pulled out specific attributes of God! I was reminded of God’s faithfulness throughout the many generations, continuing right now into this generation.