Leading media figures and insiders dismissed plans to create an editorial oversight board to protect CNN’s independence as “utter garbage” – in one staffer’s words – after a settlement was reached to resolve a lawsuit filed by a coalition of 12 states to block Paramount’s $110bn acquisition of Warner Bros Discovery.

California’s attorney general, Rob Bonta, during a press conference to announce the settlement, said that Paramount “must establish a news editorial independence board to support CBS News and CNN’s continued editorial independence to ensure independent, objective, fact-based reporting at CBS News and at CNN”.

In a legal motion to formally end the case, the companies said the news editorial independence board would “establish guiding editorial and journalism principles for the combined entity’s news channels”.

According to the terms of the settlement, the board must be established within 180 days of the closing of the deal. It will be composed of five current or former journalists with at least 10 years of experience each and will be appointed by the board of the company for three-year terms.

The board will be tasked with “resolving any disputes between CBS News employees, CNN employees and management of the combined entity regarding alleged violations of the news editorial principles”; “resolving any disputes between CBS News employees, CNN employees and management of the combined entity regarding alleged reporting bias or failure to meet agreed reporting fairness standards”; and “establishing and monitoring adherence to ethical journalism as defined by journalism industry best practices and to editorial independence, including from the combined entity’s ownership and shareholders”.

Critics of the mega-merger had expressed concerns about CNN being taken over by the Ellison family, which has well-documented connections to the Trump administration. David Ellison and his father, Larry Ellison, have reportedly spoken with the White House about potential changes they might make at CNN, which could ultimately generate more positive coverage of the Trump administration, a prospect that has worried journalists at the cable news network.

On Monday afternoon, there was already some skepticism within the media industry – including from current and former employees at the companies involved in the deal – about whether the editorial oversight board would actually protect CNN’s editorial integrity.

“There is no way that is going to work,” former CNN anchor Jim Acosta said. “They will start to fire anchors and certain folks to send a message, and the rest will either have to fall in line or leave. This was a colossal mistake.”

One concerned CBS News staffer said that it “sounds like utter garbage”.

“I’m happy to hear more about this, but how a board works day to day is tough to wrap my head around,” said a CNN producer who was not authorized to comment.

Jessica J González, the co-chief executive of the advocacy organization Free Press, expressed doubts about the effectiveness of an oversight board.

“As we learned from the failed and widely panned Facebook oversight board, a fake bipartisan oversight committee won’t save CNN,” she said in a statement on Monday. “We have all the evidence we need from the Ellisons’ destruction of CBS about what they do to warp journalism at Donald Trump’s request.”

Frank Sesno, a former CNN Washington bureau chief who now teaches journalism at George Washington University, said the effectiveness of the oversight board will depend entirely on how it works.

“I completely welcome an advisory group composed of professional journalists who can provide insight, feedback, critique and balance,” he wrote in an email. “It needs to consist of people who are committed for professional fact-based journalism and who understand the pressures and the complexities of the current media environment.”

Connecticut’s attorney general, William Tong, who was part of the lawsuit coalition, said in a statement that his state “wanted and demanded full divestiture of CNN and CBS News”.

“We wanted to save ethical and independent journalism and news,” he added. “We fought aggressively for that remedy. I am deeply disappointed that we could not do more.” Still, he said the board “will meaningfully help protect editorial independence for both news organizations, and it will be enforceable under the consent decree”.

A similar board – of five purportedly independent individuals – was put in place when Rupert Murdoch acquired Wall Street Journal parent company Dow Jones in 2007, after concerns were raised about whether the conservative media baron would interfere with the news pages. It was “meant to prevent Murdoch from meddling in the Journal’s newsroom and maintain its editorial independence”, according to a news report at the time, though some concerns were raised about the independence of some of the board members.

Last summer, Skydance Media agreed to appoint an independent ombudsman to secure the blessing of the Federal Communications Commission to merge with then CBS parent company Paramount Global.

David Ellison has insisted that he will maintain editorial independence at CNN and has contended that the lawsuit filed by state attorneys general was primarily intended to block him from controlling the network. “I believe this fight is not really about market share,” he wrote in a guest essay in the New York Times last month. “If it were, it wouldn’t have been reviewed and approved by regulators reflecting 65 countries, including the United States and China, as well as the European Union. I believe a plainer worry sits beneath the briefs and the news releases: the news. The issue is whether I can be trusted as a steward of Warner’s CNN.

“Great news organizations like CNN and CBS News are here to tell it straight down the middle,” he added. “That requires newsrooms that reflect the whole world, not one side of it. And it requires independence. Our journalists will continue to answer to the facts and to all the people they serve – not to any party or cause.”

Still, Ellison’s commitments to independence have done little to quell the concerns of journalists at CNN and CBS News, particularly as the latter network has faced accusations of holding a partisan tilt under editor-in-chief Bari Weiss.

In a statement about the settlement on Monday afternoon, Ellison made no mention of the editorial oversight board or any protections that will ensure CNN’s editorial independence.

But in a nod to concerns about partisanship, the settlement agreement notes that “no more than two (2) editorial independence board members may be affiliated with the same political party”.