Makes me wonder if this isn't one of those self-fulfilling prophecies...they were out of everything but XXXL, but people needed PT gear, so they bought XXXL...which shows in AAFES inventory system as "Holy crap, look at all this XXXL stuff we're selling, but we haven't sold any smalls"...which leads them to stop stocking smalls and start stocking more XXXL...which means sales of smalls are still way down, because there aren't any to buy.
Micheal Dell made this example...a customer comes in looking for a red Mustang, but the car dealer only has 3 yellow ones. Maybe the sales guy is good enough to talk your customer into buying a yellow one, but that doesn't mean there's mre demand for yellow Mustangs than red ones.