It technically could work, look at Kul’tiran Druids, they gain their Druidic abilities from the Drust, Druids are life and Death while the traditional Druids from emerald dream side are life focused theirs also death (Drust side) to keep the balance….
They could be more so connected to the Death Side. Even have a look at Kul’tiran forms
A lot of bone, skulls and all. It truely isn’t to far fetched to open more races to being a Druid theirs different entry points now, Emerald Dream, Wild Gods, Drust…
Look, I’m all for expanding class/race combos, when they make sense within the lore. But in this case, they don’t.
For starters, because there can never be a Tauren forsaken.
The Forsaken, as per the lore, were created by the Val’kyr (how they’re created now, with the Val’kyr gone, I have no idea) and the magic of the Val’kyr only works on human corpses, no other race.
Sure, necromancy could be used, but that would create a mindless undead creature like a skeleton in most cases.
In DnD there are Spore Druids and spells that lean more toward life and death cycles. It is not out of the realms of creativity to have Forsaken Druids, I quite like the concept and it could be a great bridge into dissolving factions and having more classes be both horde and alliance
Besides the Forsaken can’t be druids, because Druids have to have a connection to nature. The Forsaken don’t really care about nature, they’d rather see it blighted and plagued, so that’s just not going to work. No group that has connections to nature would teach them.
That’s the same reason why gnome and goblin druids will never be a thing.