That's not why he's a late riser. He was unknown to fans because Ole Miss was never in the news nor was the media talking about him. Professionals have been watching him, and at the senior bowl journalists caught wind of how high coaches think of him as a QB who have had him high the whole time.
Only malleable people who are easily influenced by news and gossip had him low. Just like only malleable people who are easily influenced by news and gossip have Sanders high. It's not a coincidence that journalists have been calling for him to slip out of the first round after catching wind of how many teams don't even have a first round grade on him.
where that gets confusing though is there are only roughly 12 players with first round grades, which means if he gets taken around 15 in the first round, he's still considered a second round talent on boards.