Thanks
@Pamuk!
My interview went fairly well. I was ready with all my documents thanks to
@Sm1smom, but I didn't have to show any of them. I was called in about 30 mins after the time. I was asked to raise my hand and swear to tell the truth. Then the lady just reviewed/confirmed the i-485 info, and asked a few small-talk/verification questions like what languages I spoke and asked for my birthday twice, I guess just to make sure I was telling the truth and I was the applicant. She asked if there was anything I wanted to add to my file, so I handed her my current enrollment letter from the school for this semester (application included previous semester's enrollment verification). I also asked her about the KCC file, because when I called KCC the day before they said the file has NOT been requested. She started going through my AOS packet looking for the 'KCC file'. I told her that based on other people's experiences IO requests a file from KCC and that DV selectees in general go through KCC. She starting typing away, and said that yes, she would need something from them. She said I should be getting my card in the mail, and told me to make sure my name was correctly spelled on the card once I got it. So I guess that was an indirect approval. It all took about 15 minutes.
I think their main reason for an interview is just to see the applicant's face and confirm their info/identity, like some others have stated. I had a stack of supporting documents, none of which were asked. I opened my folder twice to hand the interview letter to the security guard and to hand my current school enrollment letter to the IO which, again, she didn't specifically ask for, I just voluntarily added it to my file.
I'll call KCC in the morning to see if the IO requested the KCC file, but otherwise we'll see what happens. Again, a HUUUGE thanks to
@Sm1smom for all the info/assistance/hand-holding.