Mercurius
Legend
I hear you, but I think it is a bit of a conundrum. On one hand, as you say, remaining faithful to Gygax's Greyhawk would please grognards, but it probably wouldn't add too many new fans. On the other, to adapt to a modern audience would likely require changing it to such a degree that it was no longer Gygaxian.
The charm of Greyhawk is Gygaxianism, but I'm not sure how translatable that is to a contemporary audience -- at least not without changing it to such a degree that it is no longer "vintage Greyhawk."
Star Trek doesn't quite work as an analogy because it was updated only a decade after the original series ended, and then continually expanded upon and adapted over the following decades. Of course the first film was mostly a failure, but it laid the groundwork for the Wrath of Khan in 1982 - still only 13 years after TOS ended - which, of course, resuscitated the franchise. And then it continued, with no real gaps from that point until the present. There were ups and downs, but it has been overall very successful and fruitfully multiplying for four decades.
Greyhawk, on the other hand, after its "glory years" of 1980-89 (folio to City of Greyhawk box) was re-envisioned in the early 90s with mixed to poor results, leading to TSR dropping it (they cancelled a Sargent book in 1994, according to Wikipedia). Some guys at WotC were fans and brought it back, first with the 25th anniversary stuff and then as the default setting for 3E, but with minimal support. Since then, it has been rather neglected.
So to compare Star Trek and Greyhawk would be more like if Star Trek had come out with the Motion Picture in 1979 (From the Ashes, essentially), and then dropped it before Wrath of Khan, with no Next Generation. Then tried to resuscitate in late 90s.
On the other hand, and to challenge my own argument, there's Battlestar Galactica. It was dead for almost 30 years when it was brought back with a different take, and one that is largely considered to be superior. But even so, I'm not sure we can compare film/tv to RPGs.
Again, I think the challenge is translating the creative work of a pre-Boomer, who was very much the product of his time (as are we all!) to a Millenial/Gen Z crowd. I'm just not sure it is worth the trouble, and that the middle ground would be to create a deluxe commemorative box set, while focusing energy on new worlds. Meaning, I think they're already doing this, with both classic and new settings being published.
I would also add that WotC's approach in 5E is not to provide ongoing support for any worlds, except FR - and even then it is mostly just as context for new adventures, only minimally expanding the Realms.The new/other worlds aren't being expanded upon (although we very may well see another Exandria book at some point, unless Mercer keeps it within his new publishing house). There is no Ravnica line, for instance, and likely never will be. In fact, the Magic worlds are perfect for this: each provides a different play experience that can either be mined for one's homebrew, or used for a new campaign. Reviving Greyhawk would imply continued support, and i just don't see that happening. So I don't think the commemorative box for Greyhawk would be as much killing it, as reviving and immortalizing it; in other words, it is the middle ground between keeping it dead and a supporting line ala 2E/3E era, which they've obviously moved away from.
But I do think that remaining true to the Gygax vibe is crucial.
