Reading Tea Leaves...
I would think that the first thing to learn is that wild successes like Hunger Games or the Twilight movies are a manifestation of something much larger than decisions about whether to debut a movie in the Spring or Summer, or bold proclamations that "audiences like female leads!" The author(s) of the novel(s) tapped into something rare and wonderful, and there's really no way to force that. Cajole, prod, suggest and push, sure -- but this level of grassroots excitement only comes when the fans are massively engaged by the material. If marketing people could buy that, trust me, they would.
The real "lesson" to be learned from Hunger Games is to always adapt a massive best seller that's exploded Harry-Potter style across the exact demographic of young adults who like to see the same movie in the theater 7 times. Then make what appears to be a very good adaptation (don't know, haven't seen it yet) that reflects the book and manages to make real what enthralled fans on the page. Easy peasy! (By the way, I'm not denigrating the very real effort that went into producing a popular movie. It is entirely possible to mess up a good thing.)
Still -- trying to draw lessons from the success of a cultural phenomenon like Hunger Games reminds me of the old Steve Martin joke about how to make lots of money. "First, start with a million dollars!"