Sadly COVID is out of control in India that is why they banned direct flights from India but as I saw last night with own eyes, there was at least 50 students with Indian passports waiting for study permits having flown via Doha. If any of those were carrying the virus then if they went into shared accommodation then they might cause an outbreak. That said they should have had a pre-flight test so hopefully will be clean.
Within the 72 hours before boarding they could have caught covid, unfortunately some labs are also fake results and people could still test negative at the airport in Canada yet develop covid. Ontarians have had t stay home and close businesses but we are allowing people to arrive from a country that is on fire with covid. You essentially have to assume that most of the 50 people will have covid and a few will end up in hospital. Hopefully none will spread it to the community.