Yeah, the EF alerts are definitely far from reliable. My understanding is they do sweeps a few times a day to look at the inventory. But of course AA is often doing things like opening some C space and then quickly clearing people into it, which can happen entirely between sweeps. Last time I had one notify me (for LAX-AKL last month) I got the email within a couple minutes and immediately called AA; while I was on hold I checked EF and saw it was already back to C0, so I checked the AA site and saw my SWUs had already automatically cleared. So I hung up the phone.