I'm getting strong vibes of post-9/11 fervor, just with a slightly less obviously racist veneer (still racist, though). People in this state of xenophobic groupthink would absolutely support violence against China and there would be zero barrier to manufacturing their consent for debilitating sanctions, covert operations, and proxy wars. China's relatively strong position will preclude anything too direct for a while, but please consider that this will probably be the central international tendency against which we (members of the imperial core - apologies to comrades outside of it) must organize.
Please consider joining your local socialist organization(s) and taking part in their anti-war/international committee.
Discussing China on Reddit is always a lost cause. They want to believe China is the evil entity they think it is and anything confirming that will always be sufficient enough.
If they truly believe that China is doing an actual genocide, then theres nothing you can say to dissuade them.