If he doesn't beef up, Lebron will hip check him and he'll fly 8 rows deep into the crowd. I don't see him palming the ball when someone tries to dunk on him either. They'll break his arms off on the rim. That is one skinny dude. Looks like a giant alien insect. He may get drafted high, but I wouldn't guarantee his salary.
Kevin Durant was a string bean coming out of Texas and for that matter LaBron wasn't even half as big as he is now when he came out. Kid is 18 or 19 so I'm sure he would be able to add plenty of muscle when his full time job becomes working out and playing basketball. Now if he was a senior with that frame I would definitely think otherwise.