My wife's brother grew 3-4 inches and put on about 25 lbs in college. I knew a guy that grew about 6 inches in college so late growth spurts do happen. Ironically if the kid were to do that it would most likely end his baseball career.
The thing about puberty is it doesn't always mean bigger, stronger, faster, like it feels some people assume it does. My kid was big, slightly chubby, athletic, and fast pre-puberty. His 7th grade baseball coach was like "Willie Mays man". He went through puberty, put on a few inches, leaned out, and lost a step or two (or three) and some athleticism. All things being equal if that hadden't have happened he'd be in the minors instead of fighting for a spot at a mid level P5 school. You'd be hard pressed to convince me otherwise.