I believe that almost every man that isn't directly part of Revelations is at least hinted to or nodded at. I believe all the other DLC maps in Black Ops 3 have some kind of relation to certain maps, and those maps are ones that are not represented on Revelation. Example: we see no part of the map based on Moon. But der eisendrache hints heavily towards the moon map. The entire der eisendrache Easter egg is heavily built upon it. They even gave us an anti gravity room. You don't see Shi No Numa either, and i think its because zetsubou is kinda a nod tword that map. The only call back to Shi no numa that we see is the fact that the mystery box is green, and shi no numa is the only other map with a green box. I believe GK and Ascension are linked because we see The Return of gersh, they are both the only Maps set in Russia, and the Mark 3 ray gun is basically a gun version of the gersh device. There are no remade portions of the map that represent Call of the Dead or Five. But mentions of those maps are made within radios around Revelations. Mostly every map from Call of Duty zombies has been represented in some small or large way. If you noticed, the only maps that have no nodds or hints or call backs is any map that featured the tranzit crew. Not one thing reminds you of Tranzit, Die Rise or Buried. I assume this is because those Maps were not overall too popular and also because they will be featured in the upcoming comic book