Interesting. So maybe Tumblestrum's Guide to the Feywild was a product that they considered, killed, and are going to put the foundational material up as a standalone PDF. Works for me!
Based on the Dragon+ interview with Perkins posted today:
"...according to Principal Game Architect Chris Perkins, who revealed more details about this Feywild adventure at
D&D Live 2021, it’s been over a decade in the making!
“'I very much wanted to write a full-length adventure that shines a spotlight on the Feywild for fourth edition, because we’d never done one before. But when we started working on fifth edition, our priorities shifted. I was finally able to circle back around to focus on this project again once we were deep enough into fifth edition. So this idea has been percolating in my brain for around 11 years,' Chris tells
Dragon+."
"Chris kept notebooks of his Feywild ideas during that time, in anticipation of being able to return to the project. These included the makeshift plot he’d written, maps he’d drawn, and lists of unusual items that could be found in that setting. When he re-pitched the idea of a Feywild story in 2017, Larian had started working on
Baldur’s Gate III, and the D&D Team pushed ahead with
Baldur’s Gate: Descent into Avernus to tie into that product. It was another two years before Chris finally got to reopen those notebooks."
“'When I went back to my notes there were page after page of ideas for this setting. Here’s a bunch of plants and mushrooms native to the Feywild, here’s a list of fey trinkets. I kept adding to those lists and I started to flesh out the plot with some new ideas about how this could be a story about the passage of time,' he remembers."
He also notes that the Jabberwock is based on the 2E Monstrous Compendium version, that was used in only one other adventure ever...written by Chris Perkins in the 90's for Planescape.
So it seems this was definitely conceived as an Adventure during 4E to flesh out the Feywild, and has stewed a fair bit. I reckon that rather than back out of doing a Setting, that as this Adventure came together, Ray Winninger saw the potential as the basis for a whole new Setting (of which Winninger has said they are working on two right now), and they are approaching that cautiously.
