The fly over is a fact gathering terrain mapping to aid the CCP in their initial land invasion from Canada into the most unpopulated northern states.
The initial attack will include a power grid failure to large swaths of the US, which will cause chaos and divided resources while Chinese infantry take their first territories.
A very selfish part of me hopes this happens soon. Some people wont wake up until the people to whom Biden is beholden actually land in their cities and start rounding up.