It could have happened... It's so much fun to speculate in this forum. So here is my take.

Actually, I'm taking flight 66 tomorrow. I'm supposed to attend a wedding in Barcelona but I was not sure if I'd make it, so I bought a dirty cheap fare $380 round trip, on a MCE seat (first time I travel Y in half a year). I was looking to upgrade and I've been checking seats in expertflyer for the past few days. The flight was (and is) almost empty (<30% capacity) with many last minute J seats taken (upgrades?). On top of that, AA is running a promotion on low fares to EU, so they are probably running flight 66 at a loss.

To make any money, AA didn't bother to ask what instrument you wanted to use for the upgrade, so they assumed cash! I take that you assumed the upgrade was complementary. But past loyalty doesn't count. And I am not sure how current loyalty counts either. I am new to heavy flying, I became EXP last September, spent in excess of $45K in AA alone last year, so I think I'm not a bad customer (Points/Mile ratio = 1.3) and yet I've had quite bad experiences myself (granted, I had a few good ones too: complementary international J to F). Don't expect better treatment for 2MM. You are just a #, with PLT status, which has been diluted in 2013.

In the positive site, Barcelona is a great city, your destination had to make you forget any trip-related trouble!!!