You're correct on the date, sadly I was unable to find what date Ascension is set at. I have read a few different remarks about these videos, all of them say pretty out there ideas like sam kills Takeo off or that the zombies finally get to him or that he is the least favorite character and people are wanting him kicked off the game and someone new brought in. I did find several stories from people who said the same idea though, that someone being either Sam, Maxie, or another person who was Maxie's boss are telling Richthofen to kill off the others because the experiment was a failure. I personally think there are more people behind this then just Richthofen and Maxie, there bosses pr whoever got them together on this have to have some take over in this, I think this person known as the "Handler" is ment to go in and fix this failed experiment or have some part in this.