I have read an article in „Cockpit“ recently, where the responsible person from LX confirmed that the A350 will first fly to destinations at the east coast, where they are currently flying with A330.

In addition to that I remember an interview with Jens Ritter from Lufthansa saying that the US doesn’t allow new aircrafts to be flying to US destinations in the first month of operations. Therefore, I believe YYZ and YUZ will have good chances this summer.