A post here on DR1 by Windeguy.It was a screen shot of someone's phone showing someone else's FB post. Admittedly not the most reliable source. Unfortunately I do not remember where I saw it, only that I saw it this morning. If I accidentally stumble across it again, I'll link it.
Warning PCR test will be required to enter Canada with in 3 days of arrival
With a PCR Test..... the chances of a False Positive is (said to be) 0.5% So.... with an airplane carrying 175 passengers there (statistically) would be 0.875 False Positives So.... for every flight back to Canada, someone will get a False Positive and NOT be allowed to board.
dr1.com