Kung-Fu Panda is on Cartoon Network right now, and on their last commerical break they showed their movie promos or bumpers, I saw some possible footage of a future Steven Universe episode. It was raining outside, Steven's inside a building, I think he's inside the Big Donut, he's wearing a jacket and he's holding a flier. By the looks of it, it's either from Sadie's Song or When it Rains.
I can't find it, but let me know if you saw this promo just now.