In the article you write:
"At the time, authorities suspected the virus stemmed from something sold at a wet market in the city. However, it's now clear that early in
what is now a pandemic, some infected people had no connection to the market. That included one of the earliest cases from Dec. 1, 2019 in an individual who had no link to that seafood market, researchers reported Jan. 20 in the journal
The Lancet."
Below is the corresponding reference from the linked Lancet article at
https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)30183-5/fulltext
"The symptom onset date of the first patient identified was Dec 1, 2019. None of his family members developed fever or any respiratory symptoms. No epidemiological link was found between the first patient and later cases. The first fatal case, who had continuous exposure to the market, was admitted to hospital because of a 7-day history of fever, cough, and dyspnoea. 5 days after illness onset, his wife, a 53-year-old woman who had no known history of exposure to the market, also presented with pneumonia and was hospitalised in the isolation ward."
This snippet from the Lancet article does not say what you are claiming it says in your article. It says that "no epidemiological link was found between the first patient and later cases."
It does not say that no link was found between the first patient and the market. So both the first patient, and later cases could have contacted it from the market without having contacted it from each other. This is not evidence of previously undetected community spread as your article is attempting to imply.