Well, speaking of Greyhawk stuff, I just ran the module from the DM's Guild, the Second Life Charity module -
Infernal Machine Rebuild (5e) - Wizards of the Coast | D&D 5th Edition | Dungeon Masters Guild Infernal Machine Rebuild.
Now, there was a MASSIVE nostalgia trip. In the module, you travel through time to when the Tomb of Horrors was first being constructed as well as traveling to the Temple of Moloch featured on the cover of the 1e PHB. They name drop all sorts of NPC's and whatnot throughout the module. It was an absolute blast to run. Even though my players didn't really know much of the background, I kept giggling like a mildly concussed monkey as I ran the adventure. Total, total blast.
And, frankly, I think that's how a revised Greyhawk should be approached - through adventures. Greyhawk, to me, was never the Folio or the boxed set. That stuff all came YEARS later after I'd been introduced to Greyhawk through Dragon magazine, and the G series and A series and various other bits and bobs. My cousin's 1e barbarian that was a son of Kord (using rules from Dragon) was a particular favorite.
But the folios and novels? Pshaw. That's how Forgotten Realms is presented. A big old encyclopedia of knowledge that you have to mine in order to build adventures. Greyhawk? Naw, we played Greyhawk for years without even knowing what a Furyondy was beyond a mention in Temple of Elemental Evil.
To me, the recent Ghosts of Saltmarsh is EXACTLY how GH should be brought back into print. Give me more like that. How about a Ghosts of the Slave Lords? or a Ghosts of the S series? Sure, they mined the G series and put it into FR, but, why not go back to the D series and do Greyhawk style drow? Redo the I series. There is lots to mine here.