Well, it could imply a sense of new beginnings or a continuation of the journey in a different form. It might also suggest that the cycle of events in the Dune universe is ongoing, with new challenges and revelations waiting just over the horizon.
The last line might be seen as a kind of summary of the overall themes of the novel. If the novel has been about power, survival, and the relationship between humans and their environment, the last line could be a final thought on how these elements will continue to interact in the future. For example, if it mentions a character looking out over a changed landscape, it could mean that the events of the story have permanently altered the world, and the characters must now adapt to this new reality.
In my opinion, the last line of the Dune novel often leaves a lot of room for interpretation. It could be a very open - ended statement that makes the reader think about the broader implications of the story. Maybe it's a line that ties together different plot threads in a very subtle way, like a final piece of a complex puzzle. It could also be a call to the reader's imagination, inviting them to think about what will happen next in the Dune universe, whether it's in the form of a sequel in their own minds or a continuation of the exploration of the ideas presented in the book.