User blog comment:Argorrath/Treyarch posts a message of zombies; possibly hinting to a DLC 4/@comment-3091118-20130731010027

The dates on the notes are written much earlier than the origional story. As Richtofen didn't go crazy until around WW2, when he was expermenting with the teleporter and ended up touching the MPD. So this might have something to do with them, but it is unlikely. It is more likely to do with scientist who investigated the tunguska event from 1908.