So, no, S19 did not repeat any calc. He did not receive “credit” but was just placed into the next logical class for a math major at Bowdoin which is Linear Algebra. If he wasn’t considering being a math major, they still would have required one “quantitative” class but that didn’t have to be calc. It could be stats. Many, many kids do not take calc there for that requirement.
If your S does not see himself as a math or engineering major, then he most likely will either (1) get credit for his BC test and not be required to take any math or (2) have to take one math class in college to fulfill a requirement. If he’s an econ major, there will be specific math classes he will take in that major.
S19’s friends at Cornell and Vanderbilt who are considering math as a major could have started in LA as well but they chose to repeat MV. Those schools allowed that. I think those boys chose to do that to kind of ease into math in college since they already took it in high school. S19 was not allowed to repeat. The math department chair thought he was ready to move on in the math major sequence after seeing his score on a Bowdoin math placement test that all students take. Not all schools give math placement tests though.
I think you’re overthinking this. Just have him take AP Stats. It’s not going to look bad. We know kids who didn’t even do multivariable. Chose to do BC and then AP Stats. And those two kids got into Ivies.