Dune very nearly included a more detailed exploration of Arrakis' Sandworms, but it sounds like those "psychedelic" plans are being saved for the sequel. We also have word on the movie's original ending.
DUNE: PART TWO Likely To Include This Discarded Sandworm Idea; First Movie's Original Ending Revealed
Why 'Dune: Part Two,' is director Denis Villeneuve's life dream
I enjoyed Dune: Part Two, but did the characters really need to mention the movie title three times?? : r/shittymoviedetails
The Ending Of Dune 2 Explained, The Ending Of #Dune2 Explained, By Looper
In 'Dune: Part Two,' filmmaker Denis Villeneuve realizes a lifetime dream
Dune Part Two teaser poster concept by Dark Design : r/dune
Dune: Imperium – Uprising Design Diary 5: Six-Player Mode - News - Dire Wolf Digital
How do the worms relate to the political and philosophical themes of Frank Herbert's 'Dune'? - Quora
Dune: Part One' - Alternative Openings - Dune News Net
The 'Dune: Part Two' Ending Cements a Subversive Take on 'The One
Dune 2 Director Shared Candid View on Movie's Deleted Scenes: 'It's Dead For a Reason
Dune Sound Designer Reveals The Scrapped Sandworm Idea That Could Be Used In Denis Villeneuve's Sequel