In

the LCSL repeats the long debunked allegations of US biowarfare operations in Northeast China during the Korean War.

These allegations were debunked years ago after researchers gained access to Soviet-era records (link and link).

And even if archival evidence refuting the allegations was not available, some of the Chinese evidence is not very convincing. For instance, it makes no sense to drop rats/insects/lice from B-29’s in the middle of winter. The rats/insects/lice probably wouldn’t survive the drop and if they did survive, they would just die from exposure to the winter temperatures out in the open, leaving their bodies on the “snowy ground” for your grandfather to pick up with chopsticks or “bare hands”.