That article reads like the writer has a perspective they want to force, so they shoehorn examples into the story that fit the perspective, rather than an objective interpretation of Shelley Duvall's lived experience.
Notably, most talk shows then and now are rehearsed much more than people realize. What may look like a cutting remark, could be part of a well-choreographed back-and-forth.
This isn't to say Shelley Duvall was treated fairly or with the respect she deserved throughout her career and after. She may not have been.