A few major issues with the arguments presented
1. The virus is likely to have been around much earlier than September 2019, antibodies have been detected in Italy as early as Sept 2019 in blood samples of Cancer patients
The new coronavirus was circulating in Italy in September 2019, a study by the National Cancer Institute (INT) of the Italian city of Milan shows, signaling that it might have spread beyond China earlier than thought.
www.reuters.com
2. His statement that the virus has not mutated very much, as I understand it, the virus has mutated quite a bit, with a lot of different strains some far more infectious than others
The author had a goal in mind when writing the article and included facts that would support it.
Distance does not matter when populations are mobile. A bat population 1500 km away means that the virus could not be first detected in a city 1500 km away? Do not people travel, do not truckers move animals, food from one place to another, a person with an infection to another