School can't officially contact the player until the kid's name is in the portal. Back channeling can still be done though through contacts.
It's possible that contacts for KM reached out to UNC before his name was in the portal.
A couple things. 1. A lot of times AU doesn't go back after the kid the 2nd time around. 2. It's not just an AU thing. I've noticed in most transfer cases the new school who lands the recruit was not a finalist or not involved much, it at all, in the recruitment the first time in the vast majority of the cases.
Would require us going after them the 2nd time around much more than we do. A thing to remember here is a kid's rating in HS does not mean the kid will pan out to expectations in college. In most cases there is college film on the kids allowing the staff's to reassess the kids college film to see if they liked them as much as they did the 1st time.