I don't understand why the wiki shouldn't be both, a short summary followed by a longer article, maybe with additional stress on the short summaries being really, really stand-alone. When article is already in good health elsewhere, then wiki won't contain a longer article, but only because it's not needed. In other cases, shoot away. The difference from TV Tropes is that shows can't be themselves edited and incrementally improved on the wiki.

A hypothesis: are you talking about TV Tropes having two kinds of articles, short ones and long ones, linking to each other, analogizing short articles with LW Wiki, and long articles with LW Blog?