In terms of having more women on- and off-camera, Sarandon, 70, said that she believes "progress has been made." "Feud" features several female writers and directors, for example. Sarandon also said that her last four films were directed by women and that studio heads like Lucasfilm's Kathleen Kennedy show that powerful women have been making inroads in the industry.
"Just the fact that people are asking this question is a huge change," she said.
But Sarandon acknowledged that more needs to be done to close the gender pay gap. One of the reasons why it's taken so long, she said, might be the blockbuster salaries some Hollywood stars pull in.
"Not so much [progress has been made] maybe in pay, but it's such a ridiculous concept at all to pay us to do what we do that I don't know how you really apply normal standards to equal pay," she said.
The series sees Lange's Crawford and Sarandon's Davis battle for everything from headliner status to scene time to the 1963 Academy Awards. But the idea of pitting women against each other is something Sarandon said she has seen change over the past five decades.
"There's less of a tendency to push other women out because you are in competition with them. I feel that women are more supportive of each other now and they understand that together, we are much stronger," she said.
But Lange, 67, and Zeta-Jones, 47, had slightly different perspectives.
"There's a lot of similarities between what was going on then and the same thing that's happening now," Lange said. "Here's the thing, it's not going to change as long as it works financially for the powers that be ... Just like everything else in America, it's based on financial success."
"It's weird that it feels so modern watching this. And it's weird that what we think is funny, is actually quite sad," Zeta-Jones said.
But the "Chicago" star did credit creatives like the series' director, Murphy, for making "huge strides" by championing women in front of and behind the camera.
"It's a big world behind that camera," she said, adding that "we have to mix it up" and look at diversity not just on screen but when it comes to writers, directors, and producers as well.
The disparity behind the camera is just as real. FiveThirtyEight reported that between 1990 and 2015, only 2.4 percent of directors who received Oscar nominations were women. And in 2013, only 6 percent of women were calling the shots in the top 250 domestic grossing films.
"I think I know that I’ve always kind of carried a habit of submissiveness with the idea of that makes me more likable," Lawrence told ABC's Diane Sawyer about not asking for more money.
And that gender pay gap was very much there for her, too. Lawrence also revealed that she, like Portman, earned less than her male co-stars in "American Hustle."
But one thing is for certain, both in the 1960s and today -- these women aren't afraid to keep fighting for the respect and salaries they deserve.