Got an email from CIC today (subject was "A message from Immigration, Refugees and Citizenship Canada").
A message from Immigration, Refugees and Citizenship Canada
Beginning March 15, 2016, visa-exempt foreign nationals will require an Electronic Travel Authorization (eTA) to fly to Canada. U.S. citizens are exempt from the eTA requirement.
If your study or work permit was issued on or before July 31, 2015, you will need to apply for an eTA if you wish to enter or return to Canada by air on or after March 15, 2016.
If you received your study or work permit on or after August 1, 2015, you were automatically issued an eTA with your study or work permit.
For more information, and to apply for an eTA, please visit Canada.ca/eTA.
Thank you,
Immigration, Refugees and Citizenship Canada
This doesn't mention that I'm now PR, nor does it have any information relevant to my situation whatsoever. Thanks CIC... way to stay on top of things... :/