The only person laughing is usually the person who made the joke and it’s generally just irritating to everyone else who just wants to get on with their day. I might feel differently if we like, got the day off work for April Fools Day I guess
IIRC, both Canada and Australia are still tied to the British monarchy through some technicalities in their independence.
What it realy boils down to, we (and australia, NZ) still have a monarch, it just happens to be the same person as Englands. The office of the Monarch of the Dominion of Canada is not the same office as the Queen of England or the Empress of Great Britain though. To keep consistency, the whole thing has to continue or we just start over and the whole legal deck of cards is reduced to “Yeah we’re a republic now, precedence is gone, straight force for the next while instead of tradition until the new fiction gets to be traditional”
a sovereign. Being formerly of the British Empire, everything is based on the same legal fiction as England, all power derives from the crown. Any laws that are passed in Canada are signed into law by either the governor general on behalf of the monarch or the monarch themselves. King Charles can literally get on a boat and force an election in Canada if he feels the government has lost it. They have generally ceded this power and only use it in a real emergency or upon the request of parliament.