This happened with Anthony Davis and Russell Westbrook too, neither of whom were rated highly until they had their "spurts" and became physical specimens.
Also says here that Jeremy Lin was 5'3'' at 15 with a pair of 5'6'' parents, but then *bam* he shoots up to 6'3''
https://www.sportskeeda.com/basketball/11-nba-players-with-the-craziest-growth-spurts-sstl/6
Hard to believe that all these are natural, but it DOES give hope to all the young manlets out there.
Of course it must be taken into consideration that the NBA measures people with shoes on, so a guy who is listed at 6'7'' in the NBA will probably be a couple inches shorter irl, but it still seems super fishy to me.