This hypothesis also made the Chinese scientists believe that the earliest transmission in human hosts could be in July-August 2019, and not in October-November in China as is widely believed.
Apart from the unverified science, there are two problems with the theory of the Chinese scientists. First, the Indian subcontinent — they specifically singled out India and Bangladesh — is large, populated and well-traveled. It is highly likely that the returning Indian expats, in huge numbers, got infected in their respective countries, thus bringing back the range of diverse strains from different parts of the world, perhaps even from China… Second, the spread of mutated strains across the globe has not occurred in a linear manner.
This current pandemic problem is as political as it is scientific. If a scientist intends to politicise a pandemic, the most unscientific method would be the generation of populist theories without gathering further insight on their data.