Will Canadian citizens be denied entry to Canada during COVID-19 border closure?

According to this tweet from Public Safety Canada about the border restrictions on non-essential travel across the US-Canada border starting March 21, under "Permitted Travel", it includes:

Canadian citizens, permanent residents and status Indians can cross back into Canada.

So you should not be denied entry to Canada.

The messaging is not 100% clear on this. However it appears that Canadian citizens and permanent residents returning home will be considered essential travel and will be admitted. However if you are resident abroad then you will be admitted only if your travel is essential, even if you are a Canadian citizen. If your reason for travel is not essential you will be turned away at the border, and if you have Covid-19 symptoms you might also be turned away. Being a citizen does not automatically get you admitted for any reason.

Moreover if your reason for wanting to return is non-essential then you would be strongly advised not to travel from where you are now to the Canadian border, and doing so may be contrary to local regulations in the US, depending on where you are. Such travel, and subsequent travel from the border to your home would increase the risk of being infected and infecting others.

My wife, a Canadian citizen, and I, a U.S. citizen but a Canadian Permanent Resident, returned from the U.S. to Canada on Saturday, March 21. We had been snowbirds in Florida since November.

Things may change, but the Prime Minister has called for Canadians to come home. In driving, we passed numerous motorhomes and 5th-wheels with Quebec plates. At customs, we said we were asymptomatic (which we are), and were told that we were to go straight home and isolate ourselves there for 14 days, with absolutely NO leaving of the property.

We are much relieved to be home in Canada, where good neighbors pre-stocked our fridge and pantry and turned on the heat and lights for us.

Not directly an answer to the original question, and IANAL, but...

At least for the practice in the Old World, so hopefully applicable in similar legislations elsewhere, citizens have a constitutional right to return to their home country. Nowhere else it says however what happens afterwards - e.g. by current extreme-measures laws, they can be subject to quarantine lock-down, maybe not in their home but some other facility. But as long as it is on the country's territory, the constitutional right to cross the border homewards has been fulfilled.

There is no guarantee whether you'd soon get to the actual home (building) or not.

Here in Europe, generally people with permanent residence visas are also allowed to enter. Generally nobody is allowed to leave (except foreign citizens repatriating to their homelands, and truck drivers ensuring movement of food, medications etc.) to reduce migration and spread of the virus.

Likewise, with planes generally down (maybe expect repatriation/evacuation charters to go rarely) and cars forbidden to cross borders, your ability to achieve your constitutional right to get to the homeland can be compromised/delayed by technical constraints. You are allowed to leave, but have to walk across the ocean, that kind of thing.

Charter: Under the heading "Mobility Rights", the section reads,

6. (1) Every citizen of Canada has the right to enter, remain in and leave Canada.