I beelined to the YYZ black box office last week after a cancelled flight (I had been airside) and it was locked up (there was one concierge behind the desk but the lights were out, and she avoided my eye contact as I politely tapped on the glass door). In fact the entire priority lane was completely deserted; I found a wandering agent and they suggested I needed to wade into the melee at the regular AC aisle, adjacent.