Your "smoking gun" is a water pistol. The email most people are talking about is an email from someone at the Wuhan lab thanking him for saying that the virus probably came from an animal-to-human cross-species transmission.
So, if I send an email to Donald Trump thanking him for all of his service to Mother Russia, does that make Trump a Russian agent?
No!
In both cases, it's an email TO the concerned party - it could say ANYTHING! There's no collusion with Fauci & Wuhan, any more than there was with Trump and Russia! (It'd be different if the email was FROM Fauci saying something like: I hope you liked it - I did what you said and deferred blame from you. When can I expect the funds?)
At the time of the email, Fauci had made those comments - and there is no evidence of any trail back to Wuhan BEFORE then... so he said something that they liked... and they thanked him for it... that doesn't mean there was a prior arrangement, just that they were thankful for his comments!
Did Fauci reverse course on masks over time? Sure! So did Leonardo DaVinci on the possibility of flight... so did Trump supporters on the value of the COVID-19 vaccines! (Pre-Election they were all for them! Trump was a SAVIOR for steamrolling the whole process through in RECORD time!... but POST-Election, it's suddenly a Democrat ploy to inject you with super-computer chips that will control your mind and allow the government to just turn you off, like a machine.)
COVID came at us fast and furious... we were learning a LOT about it in a very short time. Remember at the beginning when you were supposed to wear gloves and use hand sanitizer when you brought home your groceries? We thought it lived on surfaces (turns out, that was wrong)... At that time, we also didn't think it was spread by aerosol... (turns out, that was wrong too)... but that's the beauty of the Scientific Method - you test your theories, and the ones that hold up you cling to, and the ones that do not, you discard! (And if you happen to have one of those theories that has held up for decades - or even centuries - and you prove it is wrong, you discard it! Truth is truth!)
But in the early days of COVID-19, we didn't want to wait for test results, we wanted to know NOW what the experts THOUGHT! Tested or not! So, the politically stupid scientists gave us what we wanted!: The unproven theories of the moment. They foolishly believed that, like any good scientist, you'd understand that some of them would prove to be wrong.
Look, there were a LOT of mistakes made in early 2020 when this first started to hit... Trump made many of those mistakes - but he's not to blame (any more than Fauci is) - we used the info that we had! We did what we thought was best at the time, given VERY LITTLE actual scientific research/results. And, predictably so, a lot of it was wrong.... hindsight is 20/20!
BUT this (mid-2021) ain't that!
We know a LOT more now than we did then - including the fact that COVID-19 does not live for long on surfaces (in fact, once the water droplets they're in evaporate, the virus dies rather quickly!), and the fact that it spreads MOSTLY by aerosol, and that masks - even simple cloth ones - do an EXCELLENT job of "knocking down" the water droplets infected with the virus and thereby SIGNIFICANTLY reducing the area around us where exhaled breath droplets (potentially COVID-19 infected) can spread.
So a year ago, Fauci and his ilk got some COVID-19 facts wrong. So did a LOT of politicians (Trump, yes, but others too... virtually ALL of them to tell the truth!).
That people got things wrong isn't the question - it's what they did/do when they find out they're wrong that is what's important! Do they admit it and correct themselves? Or, do they cling to the information (that they now KNOW to be wrong) because they don't want to admit (or look like) they were wrong.
Scientists do the former. Politicians do the latter. (Apparently even politicians who are scientists, sadly).