19 Mar From the Government of Canada re temporary permit holders:
Air Carriers
To confirm, a travel ban has been implemented through an order under the Aeronautics Act which requires air carriers operating flights to Canada to deny boarding to any passenger who is not a Canadian citizen or permanent resident (or an immediate family member). The measure came into force on Wednesday, March 18, at 12:00 p.m. (noon) EDT, and applies to travelers arriving by air.
For clarity, what this means is that international students and workers who are outside of Canada and the United States will not be permitted to board an aircraft to return to Canada, unless they are the spouse, common-law partner or dependent child of a Canadian citizen or permanent resident.