A quick opinion after all of this new information from the trailer:
How could treyarch think it was a good idea to include an easter egg, that was vital to a core game mechanic (i consider upgrading a wonder weapon a vital core mechanic) that could only be solved by translating a language that THEY MADE UP, and gave no hints as to how to translate? and thus they had to give us the translation 2 months later in a teaser trailer for the next map.
Look, I get it. People love the easter eggs, and it is very appealing to have a map that has undiscovered things that people can continue to look for. Shadows of evil on it's own is a great map IMO. But easter egg wise they wildly crossed the tipping point. Why can't they make the "achievement EE" the one that is this hard to discover, and make the ones that affect core game mechanics (opening PaP, upgrading/obtaining WW, upgrading other equipment) organic and something that just occurs as part of the normal gameplay.
I have long defended everything Treyarch has done zombies wise, because by and large it has been absolutely fantastic. Jimmy Z kind of lost his fire in BO2, and Blundell was able to find some new things that people enjoy, but he has taken it way too far, and needs to find a balance, or else he is going start losing people on this. Notice no big youtube personalities, barely any of our even most devoted members, are searching for things in this map anymore because it is just too vague, and in the end the benefit is not worth the work in-game.
Rant over, and I really hope that there is a line drawn in the sand for Der Eisendrache between story side quest type stuff, and gameplay stuff