Applying to a direct entry BS/MSOT will likely be more competitive than applying to the school in general…imo. I can’t tell you how much more…because I don’t know. It really depends on the applicant pool and the program requirements.
Is there information about the number of applications they receive versus the number of available spots? Can your son set up an appointment to speak with somebody, find out more information about the program, etc?
I would apply to direct entry programs and also have 2 safeties where he can apply the traditional route. Keep in mind that those programs can also be competitive.