I don't want to double-post so see here if you want the full details, but Citi told me today that they're swamped with applications and doing new "fraud" checks they didn't use to do (which slows the processing of each application down).

So among other things I bet the call centers are swamped with people calling random Citi number about their delayed application. (When I just now called the live person application status / recon line listed in the AA thread wiki, where the first thing they ask is the application ID, that number got answered within one or two rings. But I bet relatively few people in the general public know about that particular number, and it's not useful for anything other other than recent applications.)