I have no hard source available, but I recall that Hardby at least wasn't around during C&C Society days.
Later long-form descriptions of the city come in 2e (Circle of Eight?), in Oerth Journal I/10, and in Dungeon Mag... 109? - Looking at the Oerth Journal description in particular, it doesn't look to me as if it resonates with anything we know from the "foundation era" campaigns. More like this was really a blank canvas, more or less, that the writers chose to fill.
More like this was really a blank canvas, more or less, that the writers chose to fill.
That’s what I’ve been doing to date—my Hardby has two Colossus of Rhodes statues (one an Amazon warrior, the other an Amazon witch/seer), and stands as a bastion of Law and Goodness in stark contrast to Greyhawk’s seedy thieves with no class.
I've never ran a game in that particular section of the Flanaess, but I've looked into Hardby a couple of times, and I looked into the town's "meta" backstory back around 2013, as part of my research on a Blackmoor-related project.
I *think* Hardby might have been one of those towns that were given "stats", but had no maps or otherwise details to them. I think even the bit about Hardby being Mordenkainen's childhood home is a post-Gygax addition. Likewise, I think I remember the two statues are actually not mentioned in the Gygax-era Greyhawk-related publications, but first feature in... "The Fate of Istus"? "Circle of Eight"? - Early 2e, something like that.
It seems plausible to me that the Lake Geneva campaign simply never went there, if only because the later Greyhawk games focused on the lands to the Southwest of the domain of Greyhawk- and, because from what I understand about the Lake Geneva campaign, the game mostly used the smaller cities in the domain of Greyhawk as dominion-level fiefdoms: Meaning, the cities provided income to the PCs, but otherwise had no function within the setting. We later visit places like Hommlet etc. only because they are relevant to the basic scenario - but we never get to see, say, Verbobonc up close, simply because it's not interesting for other reasons than to provide a narrative frame.
(In case anybody wonders, while I'm mostly associated with Arneson-style D&D today through the Comeback Inn and OD&D'74, my first forays into our hobby, as a good 90s kid, happened via Dragonlance and Greyhawk. Haven't played in a Greyhawk campaign since probably 2008, but I still "keep in touch" with the setting, especially via Canonfire. Never played/ran any games set in the classic "Gygax" parts of the setting, though, but spent some good times on the Lendore Isles and in the Hold of Stonefist.)
FWIW, I think that most of the OD&D Amazon references can be assumed to originate from Hardby, based on how Gygax wrote about them in the Gord novels, and how he tied Zagig's heritage back to a family of Hardby nobles, in the Folio.
The Greyhawk Folio has brief mentions of the Gynarch/Despotrix of Hardby, including one in the past who was a "sorceress of no small repute" and had a daughter who married a ruler of Greyhawk. The Despotrix now pays tribute to Greyhawk to stay independent. It is logical to suppose the Minifig Amazon Infantry and Cavalry are the troops of the Despotrix. Due to the proximity and ties to Greyhawk, the presence of Amazons in Greyhawk city would not be unusual. In Quag Keep, the battlemaid Yevele is described as coming from an "Amazon clan force" at least one time.
Looks like Deirdre of Artifact of Evil was also from Hardby: "I am Deirdre, a knight of Hardby and minion of True Womanhood. Despite that, I serve the Circle of Eight this day, as does my boon companion, Oscar, a wizard from the Gynarchy's good lands as well."