Cross posting a bit from the other thread, just to emphasize how oddball this is to me:
There are seven named famous Dungeons located on the map, many of whi h were noy there on the original:
White Plume Mountain
Ghost Tower of Inverness
Tomb of Horrors
Temple of Elemental Evil
Maure Castle
Castle Greyhawk
Caverns of Tsojcanth
White Plume Mountain and Tomb of Horrors were printed for 5E in Tales from the Yawning in Portal in full form...but this map doesn't have any indications for Against the Giants, The Sunless Citadel, Forges of Fury, or The Hidden Shrine of Tamoachan...all of which had places on this map as originally printed.
Lost Caverns of Tsojcanth is about to be published for 5E in Quests from the Infinite Staircase...but there is no indication on the map for where the Starship in Expedition to the Barrier Peaks crashed, or for the two UK modules being printed that I can see.
There have been no WotC 5E publications whatsoever for Castle Maure, Ghost Tower of Iverness, the Temple of Elemental Evil (PotA was an homage, and the Goodman Games version is out of print) or most especially Cadtle Greyhawk.
So this particular set of 7 Dungeons is exceedingly strange. Whether this is just a collection of Eaater Eggs, or tying into something in the text of the DMG, is IMO the biggest mystery of this map
qua map.
@LaTia J you could get serious mileage out of teasing this stuff.