The factors needed to gauge cause-and-effect between media coverage and nation-level politics are so diffuse and broad that I feel it would be impossible to distinguish a world in which the tail wags the dog versus vice versa. Publishing stories favorable to the USSR is not a binary or discrete action. Neither is giving them the Pulitzer award. NYT's positive/whitewashing coverage of USSR could have been a result of the NYT reporters and editors being sympathetic towards Communists. And the government and business eagerness to have a relationship was made possible from Soviet sympathies being normalized.
Why do Chomsky and his fellow believers point to such massive hard-to-prove examples like the Vietnam War to argue systemic and planned bias between media, business, and government? Why not more everyday examples, such as news outlets' ubiquitous coverage of violent crime. As someone who's worked to procure crime data from local jurisdictions to publish for the newspaper, I can tell you that bureaucrats and businessfolks most definitely do not like publicizing this information, or emphasizing crime events, because it's bad for business, particularly real estate.
News organizations most likely have killed stories/beats for not wanting to anger real estate developers, especially developers who happen to rub elbows with the publishers and top editors. Yet if this is a systematic issue, why is the media at a local level so incompetent when it comes to managing the happiness of the local business community when it comes to crime and corruption stories? Many reporters at top-tier institutions like NYT started at local/regional outlets. Do they all have a come-to-Jesus talk with the publisher as part of joining the elite, nationally powerful outlets?