True for some universities. My university (Top 30 overall, public) does not consider intended majors as part of undergrad admissions, supposedly. Now, it would be practically challenging for a physics major to start at algebra and get up to calculus soon enough to start the physics classes, but no one would stop you. A few majors require an application in the second year, but those are specialities like journalism, business, library science, not regular STEM majors (except CS as of recently).