Are all Star Alliance's flight available for redemption with award tickets?

I was trying to get a specific flight between LIS and IST (TK1760) but could never see it in my searches via Aeroplan's website. Once, I did the search choosing business class instead of economy and suddenly I could find that flight. For some reason, it only appears for business class searches. Are there any chances that it will be available in coach if I call Aeroplan or the result I get from the Internet will be the same thing the Aeroplan agent will tell me?