An IB program is incredibly a great program. Also taking AP courses is incredibly good and helpful for admissions. NOW...remember that while we want our kids to get the best courses (AP, honors, IB, etc.) at the end of the day if our kid is in baseball, the help (hook) that baseball provides is also incredible, so coaches will be looking for "what can you do for me" now that you have the courses. My son can have all the A's in HS but if he does not perform on the field it will not matter to the coach (for that elite academic school, or any school).
I know of several cases (e.g. 1st in class IB, top 5% in elite private HS with APs) that were reasonably good players and yet did not get offers to play ball in college. At the end, is about what the HC wants and needs. The HC wants the best stud he can get that has the best grades.
The moral of the story is to take the best courses/program offered, but do pay attention to your son's baseball because the "hook" (once you have the APs,etc.) is what gets your son in, and playing. Being a student athlete is not easy, not in HS and certainly not in college, and there will always be extra work required. In addition to all the coursework, don't forget all the extra BP practices, gym work and more...it is exhausting. But it is doable.