It's a fancier way to say "story" and it's really grating. It's similar to how "looks" and "appearance" became "optics" ("this looks bad/this has a bad appearance" is now "these are bad optics") and "math" or "algebra" became "calculus" (what's the political math/algebra here?" is "what's the political calculus?"). It's the dumbing down of content disguised by fancier words.
Narrative can mean story as in "a spoken or written account of connected events", but in can also have further meaning as in "a representation of a particular situation or process in such a way as to reflect or conform to an overarching set of aims or values". So the governments recollection of how they killed Osama bin Laden is to some extent a story, but it's also part of the narrative of e.g. the "war on terror".
I'm not sure it's so much dumbing down as careless use of word. Before you teach something you often have to unlearn the things you learned as part of learning. Overuse of certain words or concepts are quite common in technology too. Though we also often make the somewhat different mistake of being too specific.
