You are correct and as I said in my 1st reply I don't know. Doing a search the only thing I found was another thread on this site. But in that discussion nobody had a real answer except that it is better to say yes than no, lying to CBSA can have serious consequences. Maybe they are just doing a survey?
And this page:
Digital currencies are not a legal tender
Digital currencies, such as Bitcoin or other cryptocurrencies, are not legal tender in Canada. Only the Canadian dollar is considered official currency in Canada.
https://amdarklimited.com/
With it saying Crypto is not legal tender, but it is not illegal to possess or trade etc., I still don't know if or how CBSA would use that info.