It’s been a long time since UNC and N.C. State played each other when both were ranked. According to Joe Giglio of the News and Observer, it’s been almost 13 years since both were in the top 25, and about 15 since both were in the top 15:
As you can see, Roy Williams is undefeated against NCSU when both teams are ranked, but those games were all last decade; Williams lost just one game against the Pack from the beginning of his head coaching career until 2013. With three games since then going the way of the team in Raleigh, this game doesn’t seem like nearly as much of a foregone conclusion as those did, even the two out of the three where State was ranked higher than UNC.