Pokemon from older times are more likely to become Lucky Pokemon. These have guarentteed 12/15 at the least ivs, and need half the stardust to power up as usual. Basically, the older the Pokemon you get from the trade, the more likely it will become a lucky Pokemon, but it has to be at least a year old to become eligible for lucky status.
In your case, your Pokemon could have a 75% chance to become lucky if from July or August 2016, or a 25% chance if from later in 2016.
