Silvermoon Builder

Silvermoon Builders are blood elves found on the Isle of Quel'Danas, during the phased glimpse seen during the Quel'Delar quest chain. They are reconstructing the newly-reclaimed isle, found around the various villages and areas (such as Dawnstar Village) that were once controlled by the forces of Prince Kael'thas.

Though the Shattered Sun Offensive has mostly vacated the isle, some members of the organization can be seen overlooking and assisting the builders in their work.

Speculation
They may be members of the Silvermoon Builders Association.