> probably illegal
It is always odd to read comments like this. Can we assume you will you be challenging this at the supreme court? The government passes laws and so it is odd to state something is "illegal" when it may not be the case. It is also odd because every country has special rules/laws around entry that are NOT the same as the laws inside the country. One of the best examples is our neighbour to the south where the border is considered a "constitutional free zone" - allowing search/seizures which are not permitted elsewhere in the country. Far more likely you disagree with it, but that isn't a legal question.
Many "covid" related actions were challenged, and the supreme court of canada ruled in the governments favour, does that mean the supreme court is also wrong? If so, who do you take your complaint to above this court?
Every country on earth has a legal right to control entry at its borders and while Canada was odd to use ArriveCan, pretty much every country demanded vaccine proof when they reopened their borders. Does this mean they all acted illegally?
The government's job is to protect its citizens, again this is why almost every country enacted some form of border control to try to stop covid, but they are all wrong?