That's my point: newer players might not have any nostalgia for Greyhawk, but they love D&D, and "history of D&D" products have taken off: my kids love those art books, for example. Positioning Greyhawk as the buy-in for learning the history of one's hobby...particularly if they include a Ruins Castle Greyhawk Adventure...I see a real market for it. And it makes more sense as a 50th Anniversary tie-in than the Forgotten Realms. The questionable nature of whether such a product would work would be why it's not set in stone yet, but whatever this project is, it is something that WotC is considering three years in advance for the 50th Anniversary, so it has to be something fitting for that while simultaneously being something they are unsure of: for the very reasons proposed against Greyhawk here by
@Ruin Explorer or
@Henadic Theologian among others, which are valid, that makes it fit the bill for the "revisit" in my mind. A Greyhawk product would be a perfect fit for a celebration of the history and origins of the game, but maybe it wouldn't sell: so WotC is still considering it and researching how it would work and be received.