Decoding social context clues

Sometimes I wonder how much the readers of a hundred years from now will miss when reading things written today. Will most readers of the future find overly subtle the things which we now view as anvils and Chekhov's guns? I know that many of today's readers when reading books written a century ago miss clues and signs that would have been crystal clear to the original intended audience. Take for example this sentence from E. F. Benson's Gavron's Eye (published in 1912):

Also it was said that, although it was a hot afternoon, she wore a big cloak.

It is a wonderfully telling line that informs the character's past and foreshadows the character's future and one that may go right by a reader today if they are not used to Edwardian writing as well as social and class conventions.

People talk much about "genre fiction" and the necessity of being genre-savvy if one is to get everything out of particular types of texts. Similarly, reading books written in earlier times or different cultures requires the reader to be "history/culture context savvy." The unsavvy reader may miss much of the careful characterization of the protagonist if, for example, they don't know about conventions that character is challenging or adhering to. Indeed they may even be aware that the character is acting in a particular way in relationship to a cultural convention because they are unaware of the convention itself.

How does one become context savvy? By doing a lot of reading. It helps if one can find editions with good annotations. Read many books from the same time/culture. Read books written a decade before and a decade after. If you are slightly obsessive compulsive you might consider ordering all the books on your shelves by date they were written so that you are aware that while Edith Wharton was writing this, Agatha Christie was writing that and T. S. Eliot was writing something else.

And if you are forced to share your shelves with someone who prefers the less heuristically useful convention of shelving books alphabetically by author's last name (within or across genres) then you at least have a publication order spreadsheet tucked away somewhere.