I can't imagine any reason for them to change this promo. This offer (1) is not a targeted offer and (2) has exceptionally clear terms.

Sure almost any idiot could've targeted VX frequent flyers more successfully using any of the dozens if not hundreds of methods employed by other airlines in similar promos. They could've saved themselves an insane amount of trouble just by limiting their promo qualifying flights to flights into / out of VX hubs (LAX,SFO,DAL) for example. Heck, they could've requested VX flight activity showing even a single recent VX flight if it really was that important to them to give their phone / email reps something to do on slow days.

Remember that JetBlue got tons of free press here - infinitely more than a less lucrative or more accurately targeted promo would. It's probably just not 5,000+ promo runners x $1000 of airfare worth of free press...