My son ended up in ML, but it was not a direct route. Lots of exploring of neuroscience, cognitive science, physics, math. I have a hard time believing a 17 y.o. Knows exactly what he would like, without exposure. What mattered most for UG was the comfort in the campus, and for grad school several profs doing research of interest.
I think you are considering many good schools, with strong CS departments. Once accepted, he can choose based on other preferences.