No, the module I mean is The Last Slave Lord by Robert J. Schwalb. This issue marks the first time the magazine has published an original AD&D adventure since way back in Dungeon #81! The adventure is for characters 6th to 9th level and most importantly is full of World of Greyhawk goodness. By all accounts Mr. Schwalb does a good job in researching the past events and characters of the Against the Slave Lords series from which this tale continues:
"The long nightmare is over. The Slave Lords have finally been defeated. Their wicked city, Suderham, has been reduced to ash, along with the slavers and their monstrous legions. No longer must the good people of the Wild Coast watch the horizon for yellow sails. No longer must they fear being ripped from their homes and carried away to far-flung lands. The victims of the slavers’ depredations have begun the long journey to recovery. A new day has dawned.
Or has it?"It does help to have a working knowledge of the A-series modules, but the cursory background provided is enough to get started. Here is some other tidbits and spoilers concerning the module:
1. AD&D players will be pleased to see concise stat lines, 1-4 sentences at the most.
2. There are random encounter charts for day and night. Gotta love random monsters.
3. The adventure takes place in Darlene map hex X4-155. Find it on your own. ;)
4. There is about 10 pages of 4th edition conversion notes at the end.
5. The underused Suloise deity Bralm is featured.
Who is the last Slave Lord you ask? Unfortunately you'll have to find that on your own if you have a D&DI subscription, I won't spoil it for everyone. If you're still curious though, just drop me a line. I will comment however that I haven't yet read into how The Last Slave Lord meshes with Greyhawk canon in the 2nd Edition sourcebook Slavers. My hope is that they don't cross over at all. Of course individual campaign tastes will vary. Download this rare Greyhawk module now!
Update 05/21/2021: Link changed to DMsGuild. Your source for all 4e-era D&D material.