Your linked article at the Sydney Morning Herald opens with a blurb saying "The discredited theory that coronavirus is a bio-weapon created in a Wuhan lab is gaining new momentum". To be clear I am not making this claim. I am however, claiming the Chinese government had an interest in biological warfare, including weaponizing SARS, and that a lab leak related to SARS research (even without intent of biological weaponry) is a possibility. I feel like the article is opening with a strawman that doesn't represent the legitimate speculation many harbor regarding the WIV lab leak theory.
Now getting back to the article's actual content - I don't think the article makes a great case for dismissing the notion that the Chinese government was interested in biological weapons. One of its sources, Luke de Pulford, is quoted as saying about the paper/book, "What’s beyond doubt is the paper’s provenance. It’s legitimate and poses questions which deserve thorough probing." It goes on to note that Xu Dezhong, who authored the paper/book, is “not a fringe player”. "He held a senior position at the Air Force Medical University and reported to the Chinese Military Commission and Ministry of Health during the SARS epidemic in 2003." It then goes on to say "Conspiracy theories are regularly published in China, including by those connected with the government" to discredit what Dezhong has claimed. But that isn't evidence that Dezhong's claims are wrong - it amounts to saying "a nonzero number of people in China have said false things before, so therefore we cannot take the word of this military official".
All that said, it is entirely possible that China was not and is not interested in biological weapons, and that the source is untrustworthy and false. But we have to process this possibility using probabilities, since there are no definite answers proving or disproving anything here. Given that China's government took over Tibet, has been oppressing Hong Kong, operates concentration camps in Xinjiang, has built up various military capabilities as it threatens aggression against Taiwan, suppressed early reports of COVID-19, arrested journalists who reported on the virus, and denied visits to the Wuhan Institute of Virology for over a year, there is no reason to trust them or give them the benefit of the doubt on matters relating to SARS or COVID-19 or militaristic goals. As Homeland Security Committee member Ron Johnson is quoted in this article when asked about China preparing biological weapons, “Does that shock anybody? It certainly doesn’t shock me."
As a side note: your mention of Murdoch seems like an ad-hominem argument, using his name as a boogeyman to discredit this story. But that's not a substantive argument.