I'm going to present some sources to you. Just the sources and quotes. You can check them yourself. Honestly, I don't know anything. And, I don't think I even agree with my own conclusions drawn here. But, I want to find the truth and I want to organize some thoughts.
Botao Xiao and Lei Xiao (preprint, February, 2020):
The 2019-nCoV coronavirus has caused an epidemic of 28,060 laboratory-confirmed infections in human including 564 deaths in China by February 6, 2020. Two descriptions of the virus published on Nature this week indicated that the genome sequences from patients were 96% or 89% identical to the Bat CoV ZC45 coronavirus originally found in Rhinolophus affinis [intermediate horshoe bat].
The bats carrying CoV ZC45 were originally found in Yunnan or Zhejiang province, both of which were more than 900 kilometers away from the seafood market.
The second laboratory was ~12 kilometers from the seafood market and belonged to Wuhan Institute of Virology, Chinese Academy of Sciences 1, 9, 10. This laboratory reported that the Chinese horseshoe bats were natural reservoirs for the severe acute respiratory syndrome coronavirus (SARS-CoV) which caused the 2002-3 pandemic.
Nature (December, 2017):
After a detective hunt across China, researchers chasing the origin of the deadly SARS virus have finally found their smoking gun. In a remote cave in Yunnan province, virologists have identified a single population of horseshoe bats that harbours virus strains with all the genetic building blocks of the one that jumped to humans in 2002, killing almost 800 people around the world.
To clinch the case, a team led by Shi Zheng-Li and Cui Jie of the Wuhan Institute of Virology in China sampled thousands of horseshoe bats in locations across the country. “The most challenging work is to locate the caves, which usually are in remote areas,” says Cui. After finding a particular cave in Yunnan, southwestern China, in which the strains of coronavirus looked similar to human versions, the researchers spent five years monitoring the bats that lived there, collecting fresh guano and taking anal swabs.
Nature (March, 2020):
As noted above, the RBD of SARS-CoV-2 is optimized for binding to human ACE2 with an efficient solution different from those previously predicted7,11. Furthermore, if genetic manipulation had been performed, one of the several reverse-genetic systems available for betacoronaviruses would probably have been used19. However, the genetic data irrefutably show that SARS-CoV-2 is not derived from any previously used virus backbone20. Instead, we propose two scenarios that can plausibly explain the origin of SARS-CoV-2: (i) natural selection in an animal host before zoonotic transfer; and (ii) natural selection in humans following zoonotic transfer. We also discuss whether selection during passage could have given rise to SARS-CoV-2.
Neither the bat betacoronaviruses nor the pangolin betacoronaviruses sampled thus far have polybasic cleavage sites. Although no animal coronavirus has been identified that is sufficiently similar to have served as the direct progenitor of SARS-CoV-2, the diversity of coronaviruses in bats and other species is massively undersampled. Mutations, insertions and deletions can occur near the S1–S2 junction of coronaviruses22, which shows that the polybasic cleavage site can arise by a natural evolutionary process. For a precursor virus to acquire both the polybasic cleavage site and mutations in the spike protein suitable for binding to human ACE2, an animal host would probably have to have a high population density (to allow natural selection to proceed efficiently) and an ACE2-encoding gene that is similar to the human ortholog.
Everything here would fit with a careless release.
One more quote, since I was curious. See, nature is a great designer. And, natural selection is how nature designs things. Consequently, I would agree (not that my opinion matters) with the Nature letter that suggests it was naturally evolved. And, that it was more evolved than the previous SARS virus.
Last one, from Scientific American (October 2018):
Chemists have sped up evolution, harnessing a process that can take millions of years in the natural world and using it—in months or weeks—to make novel molecules that today are used for everything from “green” biofuels to cancer drugs. Today that speed and efficiency was rewarded with the Nobel Prize in Chemistry.
Edit: removed editorializing.