What's true of the debate over COVID-19's origins is also true of countless other policy disputes. When The New York Post published a report on Hunter Biden's efforts to lobby his father on behalf of foreign governments, the media pressured everyone to pretend the story did not even exist. Journalists who did share the article on social media were shamed for doing so, and the uniform assertions that the paper had fallen prey to a Russian disinformation campaign swiftly persuaded both Facebook and Twitter to throttle the story. Later, when it became evident that the information undergirding the story (if not all its conclusions) was accurate, tech companies were forced to admit their error. Twitter CEO Jack Dorsey has apologized repeatedly.
Big Tech takes its cues from the mainstream media, making decisions about which articles to boost or suppress based on the prevailing wisdom coming from The New York Times, The Washington Post, and elite media fact-checkers. (That's according to information I obtained from insiders at Facebook during research for my forthcoming book, Tech Panic.) Social media companies are also wary of government officials, who have shown increasing interest in punishing them for platforming misinformation. Facebook, Twitter, et al are rationally skittish: Congress has hauled Dorsey, Mark Zuckerberg, Sundar Pichai, and others to Washington D.C. numerous times to answer questions about why specific pieces of content were allowed to exist. The best example of this was an April 2018 hearing in which Sen. Patrick Leahy (D–Vt.) printed out pictures of Facebook groups, glued them to a poster board, and demanded that Zuckerberg personally explain whether they were Russian in origin.