Several NPCs have been added to Telogrus Rift in Patch 10.2.7. Some are new faces, while a few are characters we've met before — though they weren't Void Elves at the time.
Lieutenant Verana is one of Alleria's oldest friends, serving as a ranger with her before the events of the Second War. When Alleria left Quel'thalas, Verana was one of those who joined her. Before the Sons of Lothar left through the Dark Portal, it was Verana who Alleria entrusted to deliver her gift of pendants to her sister, Sylvanas and Vereesa.
At some point, Verana must have died — as she is now both a Darkfallen and a Void Elf. Even in death, she remains fiercely loyal to Alleria.
Lyria Skystrider and Ennas the Faithfallen (previously Priest Ennas) are Blood Elves who never agreed with the decision to join the Horde, and who can still be seen arguing fiercely against the decision in Silvermoon City where — after they deliver an impassioned speech — their tune suddenly changes when a priest mind-controls them, forcing them to preach support for their leaders. Canonically, these events would have occurred during the events of the Burning Crusade, when the city was first introduced.
Now, with a way back into the Alliance, it seems Lyria and Ennas have both finally cut their ties to the Horde completely. (Amusingly, they're also quite happy to describe their hatred for the Horde to Horde players, who are free to visit Telogrus Rift after completing Alleria's questline.)