I heard that there was a secret in WoW Classic that hasn't been discovered yet. This chest requires a key that does not drop anywhere known, so could this be the secret
WoW Classic Rogue Leveling Guide - World of Warcraft Classic Leveling Guide Guide - IGN
Brotherhood of Thieves - Quest - Classic World of Warcraft
From where to buy level 25 Bullets in Orgrimmar, WoW SoD
To Steal From Thieves - Quest - Classic World of Warcraft