I have a feeling that banks in Atlantic Canada may have had the King Charles III coins, but they got a limited supply and they went like hot cakes. Same may have occurred with the Viola Desmond $10 notes when they were first released a few years ago.
It seems like whenever a new face appears on our currency, people want them and many refuse to spend them (they'd likely hoard them) until the coins or banknotes with the former face are significantly gone. I still see some MacDonald $10 notes to this day, but I have been seeing an increase in Desmond $10s in St. John's since last summer. Since August, every time I withdrew $10 notes from Scotiabank ATMs I normally go to, I got MacDonald $10s only one time, and after that it was all Desmonds to this day (including recycled ones with different prefixes). I suspect people will likely do the same when the new $5 note gets issued - if Laurier's portrait gets replaced by a new portrait.
Also, if memory serves correctly, I don't think I remember coming across any newly-minted coins in Newfoundland in recent years (the pandemic likely had nothing to do with it) except for commemorative issues of quarters and toonies - all of which had the Queen on it. Maybe banks in Newfoundland suspended ordering newly-minted coins (except for commemorative versions) due to having enough in circulation to last a while, perhaps?
Regarding the commemorative coins, I remember getting one of those black toonies in change from a supermarket, and I felt suspicious about it and turned it down in favor of a(n) (almost-)normal toonie as a result - without realizing it was real, and a special edition toonie released in honour of the departed Queen Elizabeth II.