Nope, but since we had to wait for 30 minutes to get a ground agent to let us my inbound aircraft, my confortable 1h15 connection became a stressful 45 minutes run in the airport. I went through the usual CBP OSS counters and was directed down to the bus. Of course, the bus was empty so we waited for another 10-15 minutes before moving. I ended up at my gate as the last boarding group was called. So, no, I did not notice anything different with OSS at YYZ but that may have been because I was stressed and had to hurry. Also, it was a bit late (21:30ish) so maybe they are messing around with things due to staffing or who knows what other reasons.