@GRILL
This is where I have a problem. First of all, there's a second more cingular crater to the southwest of Nuketown, so there's a possibility that one was used instead of the crater created by the nuclear blast.
image
Secondly, we know 115 was present at Nuketown before the rockets hit the earth.
And most importantly: the reason why the drilling takes place. According to what we know, there shouldn't be any need of extracting 115 in and around that particular location, after the events of Nuketown Z. Let's recount the facts we know, starting with the map Der Riese. In one of the radios, Maxis expresses his frustration at the fact that the Americans have a very large supply of 115 at one of their Nevada Bases, whilst his supply (and funding) has almost run out.
We know obtaining 115 takes tremendous work. In both Origins and Shangri-La, a lot of manpower was used to get it out of the ground. Now interestingly enough, back in Origins either Maxis or Edward already thought of a solution to this problem, the Extraction Drill. That's presumably designed to automate the process of obtaining 115, resulting in much greater efficiency. But due to unknown problems we know they never finished it because apart from blue prints it's never actually seen in Origins.
Now enter Nuketown's loading screen, the Extraction Drill is finished and fully functional, meaning whoever's using it found the original designs for it and perfected them, with the ultimate goal of extracting 115.
The biggest contradiction to me with the theory of the Loading Screen being in the future is the presence of the extraction drill itself / the reasons behind the extraction.
Obviously whoever's operating it, is doing so in order extract 115 out of the ground, but thanks to Nuketown's Season Pass (which details that the dead soldiers turned because of 115 located in a nearby base) + Maxis's intel from Der Riese (that the Americans had a very large supply of 115 to begin with) it just wouldn't make sense for someone in the future to go through all the trouble of re-designing and setting up the extraction drill, when they could've just as easily used the large quantities of 115 that was left in the bases nearby. Not to mention the fact both of the above mentioned prove the Americans either imported, or extracted the 115 themselves for studying.
Unless, the loading screen is telling us how the Americans got their 115 in the first place. How exactly did they manage to not only get 115 in the first place, but also severely more than Group 935 at the time?
Simple, they used the Extraction Drill seen in the loading screen
Following this logic: the Americans must've stolen the designs for the Drill around Origins, (+-1918) then they perfected the designs, and started extracting 115 before World War 2. By the time Maxis was asking for more funds, the Americans had surpassed Group 935 in terms of amounts of 115 thanks to the Drill. Then after the war ended, they stopped researching 115 in favor of atomic research.
The collected 115 never left their bases, so after Nuketown went kaboom, the soldiers were revived by it.
Tl;dr The US had a much larger supply of 115 than the germans back in WW2 -- before the rockets hit Nuketown -- thus they must have extracted it with much greater efficiency than the germans ever could. i.e. they built the Extraction Drill to get their 115 at an incredible rate, then moved it to their bases for studying.
As for the God of the Dead, maybe it's meant to be symbolic. Like a harbinger of what's coming?