The lightsabers on the wall in the Jedi training dojo are redressed or altered versions of previously seen weapons, including the Inquisitor's weapons without their rings, Temple Guard lightsabers, and those belonging to Jedi Masters Ki-Adi-Mundi, Luminara Unduli, Kit Fisto and Adi Galia.
Although the Jedi dojo where Kanan meets the Temple Guard was created for "Shroud of Darkness", it made its first appearance in the Marvel comic 'Star Wars: Kanan #7', published in October of 2015.