Which is Forsaken aligned undead.
All undead found in the Forsaken, and some living in the case of the leper gnomes.
I have never actually RPed with the Rotgarde outside of RP-PvP events years ago in the Arathi Highlands, nor have I been in any other PCU guild. I actually quit playing WoW actively before the PCU rose to prominence.
If an undead is part of the Forsaken, they are welcome. Provided, of course, the quota isn’t filled. Because dark rangers are the elite of the Forsaken’s military, formerly intimately tied to the Dark Lady herself, so it would not make sense to have a rather down to earth (by Forsaken standards) guild fielding massive numbers of them.
https://i.imgur.com/yAVTgmt.png
These races are all part of the Forsaken, the Rotgarde accepts quite a few of them. There is a limit to dark rangers because, as I have pointed out repeatedly, dark rangers are the elite. They are not rank and file soldiers.