One of the many meanings of "dispatch" is "an important message, sent quickly." In particular, important news stories can be called "news dispatches" or "dispatches." Actually, "dispatch from another era" reminds me of the idiom "yesterday's news," which is a negative term, for something old, dated, stale, or boring. "Burden" can be a noun for a load someone or something has to carry. It can be a verb, meaning to place a load on someone or something. Something is "unburdened" if it isn't carrying a load. Figuratively, a burden can mean something difficult. For example, if a play or a television show has to follow a clear storyline that makes sense, that could be a "burden." "Unburdened by structure" means that the show does not have any structure and does not follow a clear story line. Its a humorous way of saying "chaotic" or "formless." "Grist" is an old fashioned word that is used only in certain idioms or collocations. "Grist" literally means something that is ground by a mill. The farmer brings wheat to a mill to be ground into flour. The wheat is grist for the mill. The phrase "grist for the mill" is quite common. In the case of a TV show, it means raw story material that can be turned into a show. The phrase is a little unpleasant. It suggests that the reality show is some kind of story-making machine, and that it grinds up the Kardashian's lives like a mill grinds up grain. "Oh, isn't it terrible what happened to So-and-so Kardashian?" "Hey, it's just more grist for the mill."