Some reference before the question: Sprite's Spark is a 1st level ancestry feat for Sprites that gives a ranged unarmed attack. "The damage type and name of the unarmed attack depends on your heritage, described below; most sprite heritages not presented in this book also use luminous spark."
Now my question is, If I choose a versatile heritage for my Sprite, does it default to luminous spark, is it up to GM discretion on which unarmed attack you get, or perhaps paizo intends to list more unarmed attacks in the future?