Campbell
Relaxed Intensity
From my perspective play to find out means play to find out what happens without a player/GM level agenda for how it should turn out. It means having the ability to compartmentalize so you make rulings based on the fictional situation rather than to a desired outcome. It means you design scenarios that are fundamentally questions. It includes all sorts of play that fundamentally do not have a strong storytelling component to them. That includes Story Now play. It also includes sandbox play. It also includes B/X dungeon crawling. It also includes the sort of character focused traditional play I mostly engage in. There are tons of ways to play role playing games that do not involve GM or player storytelling. Usually some storyfinding, but storytelling is not integral. It can be valuable if that fits your group, but its not integral.