Spoke with another ATT rep. This one told me that on Thursday the system was updated with a new in-stock estimate for the iPad Air 2 LTE 128 of 7-14 business days. She was careful to emphasize that this is simply the new inventory information in the system, and could change positively or negatively before then. It seems like nobody at ATT really knows what's going on. I also know that every single Apple Store within a thirty mile radius of me has the 128 LTE models in stock for pick-up (I just checked). Clearly ATT does not have the same inventory. Why that's the case, I have no idea.
If I ordered an hour after pre orders went live and get pushed back another 2 weeks I'm going to just cancel my order and wait for them to come in the store.