What you keep posting is the traditional interpretation of the Convention (which at 67 years old, is getting a little old in the tooth, and was only ever amended in a modest way in 1967 to remove the temporal limits on the definition of "refugee") by bureaucrats under both Liberal and Conservative administrations. Of course, originally, the main purpose of this convention was to deal with dislocation caused by World War II, notably Jews seeking asylum around the world. It was not crafted in contemplation of a wave of economic migrants whose wish to relocate is only tangential to the politics of their nation of origin. After WWII refugees were resettled, there really hasn't been a new refugee crisis until what we are seeing today. For that reason, bureaucrats and governments could afford to have a generous interpretation of their refugee obligations. However, current circumstances require more conservative scrutiny.
First of all, the Convention only prevents legal penalties (like expulsion) from being applied to those who enter illegally but proceed directly from a country where they are in danger(and then promptly present themselves to immigration authorities and show good cause for their illegal entry):
Article 31
refugees unlawfully in the country of refugee
1. The Contracting States shall not impose penalties, on account of their
illegal entry or presence, on refugees who, coming directly from a territory
where their life or freedom was threatened in the sense of article 1, enter or
are present in their territory without authorization, provided they present
themselves without delay to the authorities and show good cause for their
illegal entry or presence.
Second, the Convention only prohibits the circumstances under which Refugees who are lawfully in the country may be expelled, but nevertheless allows expulsions for reasons of national security or public order:
expulsion
1. The Contracting States shall not expel a refugee lawfully in their territory
save on grounds of national security or public order.
Full evidentiary hearings are not required in all circumstances:
2. The expulsion of such a refugee shall be only in pursuance of a decision
reached in accordance with due process of law. Except where compelling reasons
of national security otherwise require, the refugee shall be allowed to
submit evidence to clear himself, and to appeal to and be represented for the
purpose before competent authority or a person or persons specially designated
by the competent authority.
The Convention also requires Refugees to obey the laws of the country to which they seek asylum.
In short, these provisions don't address or contemplate what western nations are now contending with, and it is time for governments to take a position that protects the interests of their own citizens and defend that position before the courts, asking the courts to look at the issue in this modern context. That's the approach Trump is taking (with the wrinkle that he's doing it by way of Executive Order, which raised questions unique to American law).
The Sun keeps printing articles about this because real people are concerned that Canada can neither financially afford nor properly administrate the most recent wave of "refugee" claimaints. If people didn't care, the Sun wouldn't bother printing it and the Conservatives wouldn't get any political mileage out of it.
I keep saying this because it's the standard legal interpretation of the Convention for all countries. It's why the US for instance doesn't enforce "Safe Third Country" against Mexico. There's no accepted legal basis for making that argument in the absence of a bilateral treaty.
As for The Sun - that's the same newspaper that kept running news items and editorials suggesting that Faisal Hussain was part of an ISIS terror group and hinting that they had additional evidence to provide on the issue for weeks after the government had made a statement saying that there was no such proof. The Sun will run any crap it can get away with, as long as it please Tory party brass and attacks Trudeau and minorities. It's part of the game.
And yes, there have been waves of refugee claimants over the years. There were massive Central American and Sri Lankan refugee waves in the 1980's. And there's no "crisis" today in Canada. The number of refugees accepted into Canada are a few thousand a year. The current claims have spiked due to the anti refugee atmosphere in TRump's administration and exceeded the previous budgeting for lower numbers, but that just requires extra $ allocated into the program.
The counter refugee argument has ALWAYS been that they are all fake refugees and are really economic migrants trying to cheat the system; but that's why there is an expert tribunal set up to evaluate the claims and refuse the fake ones.