"Dr. Goldstein noted that the testing paper listed the individual mutations the Wuhan researchers found in their tests. Although the full sequences are no longer in the archive, the key information has been public for over a year, he said."
If it was a coverup it was a rather poor one. It’s hard for me to think this was nefarious, unless the intention was just to delay (in a plausibly deniable manner).
If I hear a surprising claim from a pathological liar, I'm also less likely to believe it, not more!