See, a few ways you need to look at it is:

a) They probably have the premise and the 'key points' of the story figured out, just not necessarily the nuances, specifics, or how the exact story will play out in cinematic. E.g., a draft for the stories may be completed, yet not reviewed/finalized into the final copy before they are actually acted on.

B) Similarly, they are always going to be vague with respect to the future of the story and how it will play out. Giving out anything beyond what they gave is potentially just leading to spoilers.