Interesting read, thanks for sharing.
It is indeed an alarming trend for anyone who prefers to use cash (like seniors & people who are afraid that too much electronic = a slippery side into debt: like myself).
It is a subject discussed pretty extensively (& sometimes heatedly) over in the WORLD threads of CCF (& no wonder). I find it a shame how society (& even this paper) suspect the rise of large denominations being retained in circulation as a direct correlation to organized crime hoarding. I believe a lot of people don't necessarily trust banks, the stock market or other financial institutions & may hoard some of the more commonly accepted currencies (like Pound, US $ & Euro).
For another BOC researcher's take:
https://www.bankofcanada.ca/search/?esearch=cashless+ & read the PDF research doc "Is a Cashless Society Problematic?" by W Engert, B Fung & S Hendry
I think the BOC researchers look at our trend towards a cashless society as troublesome for the BOC (what will their function be if no cash?) & slightly problematic for society in times of troubles (since electronic $ is no good in emergencies/if computer systems are out, etc). Other papers I've read also recommend people think twice about it since hacking into so-called 'secure' systems is always happening so to rely on one's source of wealth primarily by one method could be dicey.