Good find. On Flyus.com I am also seeing some vacation package options with even cheaper flights on AA including a hotel (which you could throw away if you wanted).
It's interesting that Delta only gives 30% MQDs on cheaper LATAM business fares but continues to give 40% on Aeromexico discounted business. With the "bonus" MQM rollover this year I will easily have enough MQMs for DM but not expecting many MQDs, so some MQD runs like this might be interesting by later in the year -- though I suspect there are many others in a similar situation so I suspect Delta might throw us some sort of a bone by later in the year.