Here's an intriguing excerpt from the Vanity Fair article:

That fall, the State Department team got a tip from a foreign source: Key information was likely sitting in the U.S. intelligence community’s own files, unanalyzed. In November, that lead turned up classified information that was “absolutely arresting and shocking,” said a former State Department official. Three researchers at the Wuhan Institute of Virology, all connected with gain-of-function research on coronaviruses, had fallen ill in November 2019 and appeared to have visited the hospital with symptoms similar to COVID-19, three government officials told Vanity Fair. (emphasis added)

This suggests there is actually hope, and it gives even more of a Deepthroat feel to the whole thing. One question is, do they know who the foreign source is, or not? Regardless, how did the foreign source know what information was likely in US intelligence files?

It's that second question that might serve as a lead of sorts. How did they know the US had the facts, knowingly or not? They knew that that US intelligence had information about six sick lab researchers. How would they know that?

A related question is, how did US intelligence get the information that they failed to analyze? But the real intriguing point is that the source new more about the US intelligence than the US intelligence services themselves!