Obviously not when he was a recruit. I bet a lot of teams would love him right now. The big question was worrying if a 6'0 255 kid was close to maxed out. I bet a lot of teams had no idea he could jump to 280 all before he stepped on a D1 field.
Back when I used to argue against half of CB in favor of Koroma, I remember finding at least a handful of starting C's that were anywhere from 6-0-6'3 and less than 290.
He's like Jamal Aytes. If Aytes was 6'8, he'd be at a big school right now. Like you said, if Koroma wasn't 255 at his height, Big 10 schools would have been all over him. Others too. I'm glad guys like them are the sizes they are. Keeps the big boys from stealing them. Even if he was listed at 6'1 275 in HS, that would have been plenty.