If this all sounds familiar to you, it should. The original book referred to all these events. However, while Frank Herbert treated this material as background, relegating it to asides and appendixes, son Brian Herbert and his co-author Kevin J. Anderson tried to make a story out of it.
That's not necessarily an impossible feat or an unforgivable literary sin, but to pull it off, Herbert and Anderson would have to add to the story, reversing expectations to keep the reader's interest. Instead, all we get is another look at things happening exactly as described in the earlier books, sometimes in exactly the same words Herbert originally used.
While Herbert and Anderson do add some "new" elements, they're all imitations of events in the first novel. The Bene Tleilaxu invade the planet Ix, secretly supported by the Emperor's Sardaukar. Leto must rise to the role of Duke after the death of his father. The equipment and descriptions of the prequel's bullfight scenes closely resemble Feyd Rautha's gladiatorial combats, and so on.
This lack of creativity is the iceberg tip of an amazing failure of imagination.
Simplistic intrigue, scattered story
Dune was a work full of references, hidden codes and secret languages. The struggle between the Atreides and Harkonnens involved layers of plot and counterplot, creating a dense, multilayered environment in which the position of letters or unusual woodwork was just another thread in a thrilling web of information and intrigue.
Dune: House Atreides offers little of this sense of minute-to-minute revelation. There's not much new development of the ecology, linguistics, or history of the Imperium. The scenery is just scenery. It's presented to the audience, occasionally reacted to by the characters, and otherwise ignored.
Instead, the intrigues are simplistic, the kind of plots that can succeed only when the victims remain conveniently unaware of them. There are no prepared responses or hidden deceptions, no sense that the plotters are consciously engaging each other as real and potentially deadly opponents. Even decades before the events of Dune, most of these characters were already master conspirators, but here they all seem remarkably dull-witted.
It doesn't help that they're scattered across the galaxy, leaving the story drifting without a central character or focal point. Although Duke Leto should theoretically fill this central role, he only appears in a third of the book at best. Likewise, the action on Arrakis occupies perhaps a quarter of the book.
Ultimately, there's just not much of either Dune or House Atreides in Dune: House Atreides.
Without a central core to force the isolated characters together, Herbert and Anderson let their various plotlines chug along almost independently, only tangentially affecting each other. Perhaps they will intersect in future books, but this -- together with scenes, characters and subplots that seem to exist only to set up the next book -- does little to help this volume be much more than a dull placeholder, a promise of books to come and a reminder of great books gone by.