Anecdote as reply: During my times working in the UK and being obviously an American, I would sometimes chat with colleagues who were in fact "subjects" of the Crown. They were happy to grouse and complain (some) and adulate (others), but the notion of not being a subject of their royal was almost unthinkable to them. I suppose from birth they'd learned their place in society under some sort of aristocracy, and so among their goals was to achieve some level of notice from said monarch, such as appointments and minor titles and the like. I still find the mindset strange. This applied, by the way, to some subjects under other north European, non-Brit royals. Something about allegiance to their culture which included a royal family and such. Blech.
What is coming for Canada and Canadians will likely be tied to our American, non-royalist mentality, corrosive as it is and should be to "subjects."
Sometime back, there was a Freeper with whom I tussled occasionally who finally admitted his loyalty to and hope for return of the Bourbon dynasty of Europe, currently with Felipe IV in Spain. His allegiance, though he busied himself with an American conservative forum, was to hold forth on that dream of living as a subject under the Bourbons. not the Windsors, as one would have it. Go figure. Almost as unfathomable as Liz Cheney campaigning for and with Kamala Harris.
A kingdom is a good form of government IF you have a good king.