Puzzled by Brief Encounter-like story in current New Yorker

Story - or is it a an excerpt? - in New Yorker summer reading issue (cute cover, Love Stories) by David Gilbert, Here's the Story, is intriguing but finally not a very satisfying read - I'll explain, but will discuss ending of story this is a spoiler alert (assuming most who will come across this post have read story already anyway): Essentially this is a Brief Encounter story, set not in 1940s England but in 1967 LA: man and woman, each unsuitably matched although nothing particularly wrong or mean about their spouses, but they each feel misunderstood, each maybe wants to get out of the marriage but hasn't even begun to think about how to do so - story begins w/ the two of them together on a plane and can you guess where the story's heading? We flash back to a few months back, and alternate see-saw like between the two characters on a single day at which they meet by chance (they are passing acquaintances, children in the same school) in a park: he has walked out of a Dodgers game, she's with youngest daughter at a 60s love-in type festival (I'm guessing all the topical and time references have been dutifully researched). Anyway, they meet, they each go home, they think about each other, by chance they board the same TWA flight and - surprise! - flight goes down on approach to Cincinnati. I don't know if that was an actual plane crash or what in particular interests Gilbert about these two characters: we can see that it's an anti-Brief Encounter, in some way, as they are heading toward an affair when their world explodes. Maybe it's a moralistic tale - the smiting of those with adulterous thoughts. Maybe Gilbert will pick up the story through their children - he must have a reason for setting this in 1967, so maybe he develops these families further - although that would be more interesting if the two had truly had an affair and the survivors learn of this through hints and bits of evidence over many years? There's got to be some significance as well to the Dodgers game and love-in: walking out of a conventional American setting and through a Looking Glass into a different social world? No doubt about it that Gilbert writes well and sketches these two characters in every efficiently - but I'm left at the end with no feeling about them at all: they're established, and then blotted out. Stories should have a narrative arc, as I've noted in many previous posts, but this story is a flat line that ends in an exclamation point. To what end?