From Fallen London Wiki (Staging)

impossible to know. Its possible the Correspondence coal from Christmas will end up being foreshadowing. There's plenty of precedent for that. I suspect the <a href="/wiki/Caustic_Apocryphon" title="Caustic Apocryphon">Caustic Apocryphon</a> is foreshadowing, too.

The devs mentioned that part of the reason Advent became a storylet was to let them do things they couldn't do with access codes; pesumably activating living stories is one of the things they wanted to do.