Anyone working in the UAE has to get Visa's anyway. This is the majority of the Canadian traffic is it not? That being only about 10% of the total traffic on ME carriers. The rest are Subcontinent traffic with family in Canada.
Perhaps Canada wants to grant some access to UAE, but also find space for others in servicing this traffic. Turkish is up and coming, and well positioned for this. Add the fact that they are already Star Alliance members, which would mean that the companies would mutually benefit each other.