yes, this is wht i was also thinking about.
i'm lvl 31, so it seemed logic to suppose that i can get goals for other gourmet recipes available for my level.
so i've managed to collect 3 silver and to learn espresso cheesecake first (as goals required), and to see wht will come next to use my golden key.
however, nothing happened. these goals seem to be everything we get for secret club.