I can't help you with the specific situation at CLT with AA, but I have gotten several gate passes with SW over the years when picking up or dropping off unaccompanied minors. Overall, in my experience, it is very difficult, if not impossible, to get pre-check on a gate pass. The only way I have seen it, is when I was added as a gate pass to a passenger who already had pre-check.

One guarunteed way to get pre-check and to get to go to the gate, is to book a fully refundable or even a mileage redemption for much later in the same day. Then you just cancel it after you've passed security.