Well, now that i think about it, I realize that the BoC wants to keep the $10 bill in circulation. There would be financial disadvantages if the BoC retired the $10 bill - there would be no immediate impact, but there would be an impact when prices go up and the cost of, say, a single serving soft drink, candy bar, or bag of chips costs greater than $5 including taxes. The demise of the $10 bill would eventually lead to the number of $5 bills in circulation more than tripling, which means a lot more money would be spent on printing millions and millions of additional $5 bills, which in turn could be a major financial impact for the Bank of Canada.
I did learn from a retired RBC employee many years ago that $10 bills are not ordered by many banks because most customers do not want them. If it were their choice, they would rather $5s and not $10s. I don't know if the mass refusal of $10 bills by customers is linked to Sir John A. MacDonald's likeness, and that Prime Minister did a lot of things that were deemed controversial. Whatever denomination of new banknote has MacDonald's likeness on it, if the number of bills of that denomination goes down sharply, the reason will be pretty clear..
Newfoundland and Labrador, where I live, has not seen very many of the Desmond $10s to date (most of the circulating $10s in my province are of the 2013 and some of the 2017 commemorative series - but the Desmond $10s are so rare at this point. I do know there was a large number of 2013 $10s with prefix FTV in spring last year, and last fall there were some FTTs. This implies the banks that have $10s likely have stockpiles of $10s that they had a hard time going through (I have yet to see any new $10s with the Macklem/Poloz signatures) and the way things are going, the inventories of $10s may not be depleted until much later this decade.