hi winteriscoming. i think it applies to permanent residents returning to Canada; so those who have landed or settled na dun as they should have been issued with a PR card. so for first time immigrants, i think whats needed for landing are just those documents provided to us upon approval of our application like visa on our passports, CoPR, etc. Once we have completed our landing and settled na dun and then received our PR cards, then it will apply to us na. hehe basically to me it only means na permanent residents na lumabas at babalik ng Canada by air must present their PR cards or permanent resident travel document (which ever applies) and valid passports when they return. kasi may nabasa ako before, kahit daw expired na ung PR card does not necessarily mean di ka na PR, so there are options like applying for permanent resident travel document if you are outside Canada and do not have a PR card or your card is expired. eto po ung link:
http://www.cic.gc.ca/english/helpcentre/answer.asp?q=065&t=10
"Note: As of March 15, 2016, permanent residents returning to Canada by airplane will be verified before boarding to ensure they hold a valid permanent resident card (PR card) or travel document. Don't delay – get your PR card today. This card is official proof that you are a permanent resident of Canada."