The Previously On isn't "promotion"; it's to catch people up. TV can't win in this case since you had trouble keeping up with the story in The Wire but then you claim it isn't art because it has Prev On aimed at helping you keep tabs on what had happened.

And commercial films that are parts of a series often have teasers now for the next film. Nevermind that trailers that precede the film.

Mostly though, the idea that plot driven is somehow less artistic is confounding to me. The vast majority of films that are made are plot driven. The Wire added moral dilemma to the basic whodunnit element of their plots but then you complain that there's too much moral dilemmas.