Not sure how comparing crossing the US/Canada border with someone travelling from Lahore can possibly be the same thing other than both involve CBSA
For a start they will need to be able to demonstrate to the airline checkin in their home country that they are genuine immediate family members authorised to travel and also possibly to CBSA at the POE plus of course will be asked about an isolation plan.
The last time i checked there were no special privileges for USA citizens... plus I only mentioned that one person was returned at the border... whereas other people are still traveling by plane... so why is the comparison so bothersome? None sense...
As for the demonstration of the relationship, that’s another story. The OP asked whether they would be able to travel. I said yes, people are traveling even from USA, which btw is being seen very negatively from Canadians and I would say even CBSA...
And to confirm OP, one lady I know just came from Pak as parent of citizen from Multan... so don’t worry. Just have the docs super ready!
- get proof of relationship
- print of the IRCC page showing that they are exempt
- quarantine plan 14 days (give a solid plan, ask CBSA for unofficial confirmation by phone)
- tell your parents that when asked reason of visit, they should say: “we are traveling under the exemption from travel restrictions in place from June 09, 2020” and show the paper with the exemption on it!