The Urbane Druid has been around since 3.5e days, they view the city as another ecosystem which is what makes them so compelling.
I shouldn't have mixed the idea of Blight Druid and Shadowfell Druid, as they would be totally different (one is the Druids of Blight , Poisons, and Diseases which are natural, which tend to follow Talona in FR).
My idea for the Shadowfell Druid was based on the realization on just how different a Druid raised in the Shadowfell would have of nature compared to a material plane druid.
Like Undead are unnatural horrors in the Material Plane and Feywild, but in the Shadowfell they naturally occur, so a Shadowfell Druid who have no problem with undead, as long as they stay put. This Druid would take care of the Shadowfell ecosystem, but also make sure that toxic things like Undead or invasive species stayed in the Shadowfell and did not leak out into other planes. They wouldn't nessasarily be evil, but they'd weird out most other Druids.
The Lycanthrope Druid would be based on a previous Druid Kit from 2e I remembered from Baldur's Gate.
They traded regular Wild Shape for the ability to turn into a Werewolf (including hybrid form), they WERE Lycanthropes.
In 5e they wouldn't give up regular wildshape, but instead gain the Lycanthrope Disease, although no alignment change. That includes not just the shape shifting ability, but also the other effects like being able to spread Lycanthropy. Might need tweeling for balance.
For Circle of Elements I'm think of a more Darksun style Druid or one devoted to the Elemental Gods of FR.