Despite my own access to lots of old Ravenloft material, I purchased and really enjoyed
Van Richten’s Guide to Ravenloft. It was a fresh, quality modern reboot that gave my groups a clean start
unburdened by truckloads of past material, official or otherwise. We were able to make Ravenloft our own all over again, and it felt good! I’d gladly welcome the same for Greyhawk.
If that doesn't happen and I still feel the urge to campaign in Greyhawk like I did in the 80s (I'm 53), I’d do what
@Parmandur suggested - I'd get the PDF of the World of Greyhawk boxed set and start fresh as if no other material existed, making the world our own all over again...