Going to give you a more detailed version.
So my wife and I went to the USCIS center. They called my wife and I told the officer about the pending i751. He said that right now, he is only concerned about the n-400. He asked me if I am the husband and I said I was. He told me to hang back in the waiting area.
My wife cleared the n-400 and she said that he did ask some i751 questions to her as well. The officer told her that he did not make a decision yet but most probably will clear the i751 as well. And if he has any concern, he will contact via mail.
I had no idea how to respond as I felt this is very vague.
But today, the status of the n-400 application has changed to "Oath ceremony will be scheduled". But the i751 status remains the same at "Case was updated to show fingerprints was taken."
I will wait to get the official notice of oath ceremony in hand!