I think the key here is that OP is a freshman. There’s no need to go into a high-pressure math track that s/he feels unprepared for, considering there’s plenty of rigor in the rest of that top prep school curriculum. Students with a decent GPA from that school WILL get into good colleges. In addition, this may “allow” OP to look elsewhere than HYPSM/Williams, and check out the many excellent colleges out there instead of going straight for prestige. Suggesting OP will not be able to do premed or business is false…
(the GC may not be aware of it, but plenty of students start with precalculus in college, including premed students and business students… Premeds often do in order to prepare for calculus, because you’re right, jumping straight into calc in college is tough, as for business students it depends on the business school’s pool of applicants.)
OP: if you don’t have calculus, “offset” it by doubling up in science, or by pursuing two foreign languages at a high level, this will be satisfactory for basically all the colleges you may want to look into. Also, remember that you don’t have to major in business to work in a business - your job will depend on the skillset acquired in your major - philosophy or statistics or neuroscience or Arabic - as well as your internships, not on the exact title of the major.