Yes, there was an announcement to all participating travel agencies back in May where they openly stated that relations had been disrupted by some action (unspecified) that Air Canada had unilaterally taken to the detriment of the travel industry.
My guess is that AC
began implementing web fares way below those available to us, travel agents, and thus rendering Sabre and GDS as a whole uncompetitive on most routes. This is most unfair and goes against the principles of business parternship.
As a retaliatory measure, Air Canada is never shown as a first travel option when requesting a route display between two points and AC
options are only displayed if specifically detailed as the only-choice carrier. Sabre refuses to show (and therefore, it is impossible to book) any First or Business class inventory available on any AC
route anywhere in the world.
Since Travelocity is a subsidiary of Sabre's, I guess this is the answer to your question.
Greetings from Nomadas Travel in Cancún, México !