Many Powered by the Apocalypse games make an agenda item of playing to find out what happens, discarding notions of “this will be my arc and this is how any particular scene from it will go” and looking to the unexpected for maximum fun and excitement.
Masks: A New Generation has a particularly different phrasing, “play to find out what changes”, and the long description tells me a lot of things that read rather like “play to find out what happens” with a new coat of paint.
You don’t know exactly what will happen over the course of the game. You don’t know who the PCs will become. You don’t know how they’ll change the city. That’s why you’re playing in the first place—because you’re excited to find out! MASKS is a game about change, about young people growing up, about the city reacting and reshaping itself in response to the people within it. Don’t plan on any single course of events coming true—plan only on pushing and prodding the characters and the setting to see what it might become.
What is the key to understanding this agenda item, and how do I best fulfill it without leaning too heavily on a Dungeon World background (as the GM and as a player)?