Scars Unseen
Hero
They did it in a really good way, though. In a way that expands the setting, rather than compacting it to fit in an existing box.
The Feywild is added as "Lands Within the Wind", isolated pockets of wonder and life, which have mostly been destroyed. Those that haven't have hidden away from the world, as the Sorcery-Kings would love to get their hands on all the life-force inside.
My problem isn't expanding on a setting: it's "expanding" it by forcing in elements from the core just because it's core. Especially when they do the same thing with every setting. It's not creative to fit the feywild into the setting when that's what you're also doing with Dragonlance and the Forgotten Realms, and so on. That's what I mean by homogenization. The settings introduced by TSR were good in part because they were each completely different from each other. Especially with some of the quirkier settings like Planescape, you could feel the creators' touch in the books. Now everything feels so designed by committee that I just don't see much point is spending money on the books.