The about-face on the lab leak theory felt very orchestrated to me. In particular the public finger pointing linking the scientists decrying the theory and their involvement in gain of function research and those that funded them also promoting a zoonotic cause. There is a juicy rumour floating around recently that a high level Chinese intelligence officer has defected. I can't find any reliable sources talking about it, but haven't looked very hard either. https://redstate.com/jenvanlaar/2021/06/17/breaking-chinese-defector-confirmed-as-top-counterintelligence-official-n398374 https://www.thedailybeast.com/rumors-of-us-secretly-harboring-top-china-official-dong-jingwei-swirl This move is going to piss China off so badly, that my guess is that the administration already has the evidence they need to make a reasonably certain conclusion.
It's an interesting angle, but I would be more confident were the source something other than Red State, a notorious right wing rag. They can't resist conjecturing that one of the main pieces of intel that the alleged defector has provided has to do with Hunter Biden's computer. Total lack of credibility.
The whole thing sounds too fanciful to me, I just remembered your comment when I read about it. I think it might be clumsy US disinformation - the dailybeast article mentions the rumours spreading through the anti-CCP Chinese media. Dong’s defection was raised by Chinese officials last March at the Sino-American summit in Alaska, according to Dr. Han Lianchao, a former Chinese foreign ministry official before defecting after the 1989 Tiananmen Square massacre.