I don't think it's necessarily a bad departure from source material to make the blindly devoted wife into an intelligent, self-thinking presence. Call me woke or whatever but I think it has a lot of interesting potential for a love interest to counter what otherwise becomes an absolute authoritarian autocrat.
I never understood the people who get upset that a film is not 1:1 with the source materials. The story on film doesn't have to, and in many cases shouldn't, be lock in step with a book almost 60 years it's senior. This medium is not just for the book reading audience. It's for casual film goers and cinemaphiles as much as it is for sci-fi nerds and the book lovers. Not to mention, the director and script writers are their own storytellers just as much as Herbert was. If you prefer the books, they absolutely still exist.