Closely related viruses have leaped into humans twice in the last 17 years via completely standard zoonosis, neither time of which was directly from bats but instead through an intermediary amplifying animal. While a laboratory keeping a culture of or animals infected with a wild virus is a possibility, as is laboratory accidents... these things DO happen naturally.

I must also reiterate that the sequence analyses reveal that all the interesting attributes of this virus were already present in a closely related virus that has been circulating in bats for at least fifty years, and there is evidence that related viruses have passed through pangolins.

What is the proposed timeline of this theory? There are known patients in China that have been confirmed as infected in the community as far back as November 17 now...

An update. 

This recent article by Nicolas Wade: https://thebulletin.org/2021/05/the-origin-of-covid-did-people-or-nature-open-pandoras-box-at-wuhan/ is particularly damning, going into details into many lines of evidence all pointing towards COVID-19 accidently being released from the Wuhan Lab.  

I recommend anybody interested in reading the article. It has made me update substantially towards an accidental-lab-release origin for COVID-19.

My current estimate for such a lab-release origin is ~85%. 

Update: Some further googling brought up some skepticism towards some of Nicolas Wade's claims, here and here

my best estimate is now 65% for a lab-release. This is still a substantial update from my initial ~20% for a lab release origin for COVID-19 (estimated in hindsight).

I would like to see someone collect information about this hypothesis is a more organized fashion (not a youtube video), specifically to outline which labs are a possibility, who the people were at the labs, what their prior publications were, etc.

Also, for the other zoonosis, how did they arise? (I.e., in a city? In the country? etc.) Same question for other lab escapes.

This Nature article argues that two new features of SARS-CoV-2 look like they've undergone selection for humans or human-like hosts: the "receptor-binding motif (RBM) that directly contacts ACE2" and the "polybasic (furin) cleavage site". They argue that the virus had to acquire these features somewhere other than bats, and investigate several hypotheses:

https://www.nature.com/articles/s41591-020-0820-9

1. Natural selection in an animal host before zoonotic transfer
2. Natural selection in humans following zoonotic transfer
3. Selection during passage

They think the third option is unlikely, though I don't entirely follow their argument:

"In theory, it is possible that SARS-CoV-2 acquired RBD mutations (Fig. 1a) during adaptation to passage in cell culture, as has been observed in studies of SARS-CoV11. The finding of SARS-CoV-like coronaviruses from pangolins with nearly identical RBDs, however, provides a much stronger and more parsimonious explanation of how SARS-CoV-2 acquired these via recombination or mutation19.

The acquisition of both the polybasic cleavage site and predicted O-linked glycans also argues against culture-based scenarios. New polybasic cleavage sites have been observed only after prolonged passage of low-pathogenicity avian influenza virus in vitro or in vivo17. Furthermore, a hypothetical generation of SARS-CoV-2 by cell culture or animal passage would have required prior isolation of a progenitor virus with very high genetic similarity, which has not been described. Subsequent generation of a polybasic cleavage site would have then required repeated passage in cell culture or animals with ACE2 receptors similar to those of humans, but such work has also not previously been described. Finally, the generation of the predicted O-linked glycans is also unlikely to have occurred due to cell-culture passage, as such features suggest the involvement of an immune system"

I think their argument boils down to "it's more parsimonious that SARS-CoV-2 ended up with RBD sites with ACE2 affinity via recombination with a pangolin virus than that it acquired it via selection in animal or cell culture, given the virus had not previously been described". I think this argument could be made cleaner, and that better steelman arguments for both "lab escape" and "zoonosis" origin could be produced.

To me it sounds more like a screw-up than a conspiracy. [Also check out the origins of the term "conspiracy theory".] This is *not* the theory that this was a bioweapon that escaped.

There was a paper a while back not peer reviewed and 'withdrawn' and the Chinese authors have been keeping a "low profile" ever since:

"The possible origins of 2019-nCoV coronavirus" now at https://img-prod.tgcom24.mediaset.it/images/2020/02/16/114720192-5eb8307f-017c-4075-a697-348628da0204.pdf

by Botao Xiao
South China University of Technology

I have been following the youtuber's channel of the video in the OP for a while and found it good value for understanding China. Whether this theory is right I am not sure. But nothing in this surprises me. Yes he hates the CCP but what that may not be entirely irrational.
Things that make this possibly more likely:

• Cover-up - CCP always covers things up, blame others (e.g. Chinese foreign ministry spokesman trying to blame the US for the CV)
• Slack procedures - There have been many leakages of infectious material from Chinese labs
• Selling infected animals at markets - not at all surprising in a country that has been through what the CCP inflicted in China. You do what you need to do to survive....

We will probably never know for sure as long as the CCP is in power.

1. This is not particularly credible.

2. It's also not particularly important.

3. Even if it were 100 percent true, it would be what I believe Less Wrong likes to call an "infohazard". Unless you want to literally get people killed, you don't want to spread this stuff.