To answer my own question: still not open as of 6/28. The check-in agent was very apologetic and had no estimate on when it will open.
Originally Posted by
PremiumSeat
I was just at YYZ this past Saturday and the ladies at the general information desk in the U.S. departure terminal said they were informed that it’s reopening this Tuesday (on June 20, 2017).
Any updates in the last few days? I will likely have a few hours to kill at YYZ tomorrow and it would be great if the Admirals Club were available. The AA website still says it's closed, but I'm hopeful based on this comment.