I've flown AA for decades, and I don't believe I've ever heard or seen the expression "passcode." I most certainly have never been asked, over the phone, for my password on any account, anywhere, ever. If anyone did, I would hang up instantly! One nice lady did ask me for my account number: that made me laugh since I hadn't really thought about why or how I had it memorized ....

As for the "security question" conundrum, I've always been careful to select fixed, immutable things with a single invariably correct answer since (as noted above) memory fades over the passing years. My favorite questions, therefore, are something like, "What was your first X?" or "Where did you first Y?" Believe me, there are some things in life you never forget.