There is no question he has the talent, but his body failed him down the stretch. When you are drafting in the lottery you need to be damn sure that the guy your getting can last 82 games and contribute.
Yes people do develop in the NBA, but the NBA moves on from people very quickly if they aren't ready to contribute. There are very few second chances for guys that aren't ready immediately.
If he comes back with his body improved showing that he can withstand a full college season, then I think more teams in the top 5 will be willing to take a chance on him. With the exception of Zion Williamson or Anthony Davis, no NBA team is drafting a guy who isn't ready for an 82 game schedule next season in the top 5