I was undecided coming out of high school. I purposely chose a college with many general education requirements. so that I could take classes in many subjects to help me decide. The plan worked. I graduated in four years with an economics degree. I’d encourage your son to use his time to explore some career paths in his area of interest, make use of college career planning and job fairs, do internships and use his time in college to hone in on a career starting place.
My older daughter chose a decidedly pre-professional path. She used AP credit for literally all of her general education requirements and has focused entirely on engineering in college. She’s been very happy with that. Second daughter chose a liberal arts college but has already chosen her major and a minor and plans to graduate in three years. Son will likely be pursuing a particular major and career path straight out of high school and would prefer to never have any classes outside of that path!
There’s many ways of doing things and many ways of getting from high school to a fulfilling life and career.