Agreed ! Also even though the n400 is under the 5 year rule, the whole immigration journey/file can technically be reviewed. It happened to somebody i know, the petitioner actually got very nervous as the I/O was poker faced and my friend could not understand why he asked him things related to marriage even though AOS and ROC had all happened smoothly years back without any RFE's etc.
Better to be prepared than have a deer in the headlines moment.
Best of luck