Well, it's more like: they tweeted links to published claims that it was a US bioweapon from a think-tank based in Montreal (Global Research Canada), in direct response to outright claims by US politicians & government officials that it was a Chinese bioweapon. You can read a detailed timeline in this report from the Atlantic Council:
The citations on wikipedia don't seem to be about tweets. Although you may be correct about the tit-for-tat nature; two wrongs do not make a right. China's government intentional stoked conspiracy stories and this nearly-whataboutism doesn't actually help anybody figure out what's going on.
> Hua Chunying, a spokesperson for China’s foreign ministry, said on Monday (Jan. 18) at a press conference that the US should open Fort Detrick, a military medical research base in Maryland, for further investigation as a possible origin of Covid-19
> ...
> Hua made the remark in response to a question on China’s reaction to a statement last week from the outgoing US state secretary Mike Pompeo, who said the US government has “reasons to believe” some staffers at China’s state-owned Wuhan Institute of Virology developed symptoms that were consistent with “both Covid-19 and common seasonal illnesses” in autumn 2019
You're talking about "whataboutism" in a thread about the Pentagon and General Dynamics intentionally spreading misinformation about Chinese vaccines across Asia, including that they contained pork. If that's not "whataboutism" then "whataboutism" is a meaningless, disgusting term forced on Americans in the 50's to explain why the US shouldn't answer for apartheid, but socialism was the worst danger the world had ever seen.
https://www.atlanticcouncil.org/wp-content/uploads/2021/02/W...