They become comedians? I once met Kevin Brown, “Dotcom” from 30Rock and he told me he was an engineering student. I asked “What happened?”
His reply: “Multivariable Calculus”
My observation is that for many schools you have to apply to the “Engineering College” within the University. If he wants to “drop back” to an "easier’ major, there isn’t an issue as they are not as competitive.
At this point this is not something I would worry about. He has to do well in his HS classes, get into college, and then see how he feels. If he didn’t like something…what aspect? I was an Electrical Engineering major and found out I did not like circuits … I got through that and have a job that uses the problem solving skills and is in the technical area but I am not designing hardware.