Edit: For weather.
I don't think Canadian ovens feature the Fahrenheit scale because they are sold in the US. The SKUs are likely to be different and changing the display is easy. Consider cars which are similar. I assume Canadian cars feature speedometers in KPH and external thermometers in Celsius. I am curious what units your engine coolant temp uses though!
Canada is a commonwealth country and the commonwealth didn't begin converting to the metric system in earnest until the 1970s. This is over 100 years later than the rest of the world. Canada paused metrication in 1988. Cooking is likely to have been one of the last things to change because it is so common.
Pre-metrication Canada used the Imperial system and the US used the US Customary system. This means the definition of units like the gallon was inconsistent. Units in Canada seem to be influenced more by the commonwealth than they are by their southern neighbor.
A lot of things in Canada are imperial because of the influence of the US. The Ontario building code says when framing a house, wooden studs need to be on 406.4mm centers. That sounds like a really weird number, until you realize it’s actually 16”. It has to be metric, but it also has to evenly divide 4 feet, because drywall here is 4 feet wide so we can import/export from/to the US.
Seems more likely to me Canadian sizes are the way they are because of the Imperial system and commonwealth history.
The US never used the Imperial system so even when both countries used gallons they were different sizes.
The BBC's weather reports are all in Celcius: https://www.bbc.com/weather/2643743
275, 375, 400, 425, and hot are arbitrary settings to me, not particular temperatures. They're comparable only in that they're ordered. This is not an understanding of the scale, beyond knowing that it's talking about temperature. I definitely could not tell you how 100f relates to a standard room temperature of 18C
If you give temperatures in Fahrenheit, most people outside the US (and Canada) are going to need to convert that to Celsius.
Fahrenheit-literacy, at least in Australia, is practically zero for anyone under 60-70 that has lived outside the US.
Even folks who grew up with it. In Australia they have have spent the last 40 years using Celsius for everything. You tell them something in Fahrenheit and they're going to pause, have to think "How do I convert that".
But anyway, the point was that it's not false to say "The US is basically the only country in the world that uses the Fahrenheit scale."
Basically everywhere else DOES use Celsius.
For day to day understanding of weather and climate, using anything other than Celsius is going to confuse or frustrate more people than it's going to help. Regardless of whether they're in or out of the Commonwealth.
UK Metrication: 1978 (partial)
Canadian Metrication: 1976 (partial)
Australian Metrication: 1988
NZ Metrication: 1976
French Metrication: 1858
German Metrication: 1872
Mexican Metrication: 1857
At least where I am, Celsius is the unit of choice, even among the older generation.