China does not want war, but China is not afraid of war. Proven in previous encounters.It's going to be very obvious if there is ever a genotype engineered bioweapon. If that is the case, China would immediately understand who and what caused it and will simply respond with the like OR if the weapon is deadly enough, with WMDs. It hopefully will not exit without taking all of Europe and the US with it BUT it needs to ensure that the suspected perpetrators are indeed the ones who executed. This is exactly the rationale behind MAD principles (discussed in the past in the BM thread) that basically make it an imperative to target and take out every major stakeholder, allies included. MAD principle is remarkably obvious and easy but clearly out of reach for some morons out there.
I imagine if the US or whichever instigator has any such grand intention for any major power (all US main competitors and would be competitors are), the targeted nation, would do everything to bring about as much MAD as it possibly can. A genotype targeting virus is fairly easy to suspect and verify. Once it is, it's all out nuclear detonation and any other weapon that's in store. If you think it takes too long to verify, before the problem gets bad, every nation would go all out offensive on suspected instigator/s before it ever gets to a stage it is too weak to do so. I believe if your theory has any truth behind it, the motivations would have been to instigate a global fallout and depopulation event with the expectation that targeted nation/s would retaliate in full. Can they hide their hand well enough though to have plausible deniability? Imagine if China unleashes a genotype bioweapon on India, India would verify it is such a thing and be totally justified in mounting an all out attack on China using nukes and whatever it wants. It would be impossible for China to create enough plausible deniability. In the real world, even if the US did the crime and blamed it on China, India would still follow through. I think that would have a higher chance of happening than China doing such a pointless thing. US wants to see China at war with others and getting bogged down. As long as it's creating obstacles for it, the Anglo US elites will throw whoever they control under the bus just to get their way.
But Xi Jinping's warning during the 100 year anniversary seems to indicate that the powers that be might suspect or know of a far greater depth of US/adversary antagonism for him to so publicly say they will crush whoever wishes to destroy China.