He'll be fine. One is not a prereq for the other.

AP CS Principles is viewed as a weak AP by many colleges. He probably should skip it.

Yes, AP CS A is very easy for coders

I took AP CS AB back in the day concurrent with Algebra II/Trig. There's not a ton of math to AP CS - that comes later in college when you have to apply logic (sort of geometry, although formal and boolean logic are more helpful) and discrete math to your CS.

But I don't know if these days AP CS A builds on the AP CS Principals class that didn't exist back when it was AP CS AB.

My kids' school doesn't require Principals before CS A, for what it's worth.

My son wants to take AP CS A next year, but his counselor is concerned because he has not taken AP CS Principles. Should a student who has completed AP AB cal and is on his school's robotics team (coding component) be able to handle the class? I legitimately don't know. His math teacher from last year says it should be ok, his AP AB Cal teacher declined to weigh in.