Villeneuve revealed that he has envisioned not just a two-part adaptation of Dune, but its sequel novel Dune Messiah as well. In response to question by Screen Rant‘s Ash Crossan, Villeneuve said, “The thing I envision, the adaptation of two books, Dune and Dune Messiah. We decided to split the first novel in two, so now we are at three movies. Those movies are very long to make. For my mental sanity, I decided to just dream about three movies.”
Yea, it's pretty weird but also perfectly inline. Granted it jumps forward like 3400 years or something, and Leto Atreides is a freaking worm..
I know some people don't like the books that Frank Herbert's son wrote, but I like all the lore that was in the Legends of Dune series and explanations why the Atreides and Harkonens are rivals.