Same experience here. The school is held in high regard but I just have not encountered many alum in IB or finance (clients) in general. IB as I am sure you are aware (or you wouldn’t be asking the question) does still tend to incorporate a heavy element of alumni networking and “target” school recruiting.
We know several kids however that have gone on to med school careers and had great Wash U undergraduate experiences.
Congratulations on his being a recruited athlete. Perhaps the coach can link him to some former teammate alum who have similar professional aspirations.