Another counter point is that cash is arguably easier and more convenient in some aspects for some people.
Maybe you could possibly argue this way if upon freezing their accounts they called them up and said "Hey, your account is closed, come pick up your cash", but I'm pretty sure that is not the case here, and it is rather more like a civil-asset-forfeiture situation, where they'll likely need to go to court to regain access.
Now, all that being said, this is Canada, so I don't honest know whether there is an equivalent to the 5th amendment in their charter of rights, or whether there is some legal weasel word (e.g. "reasonable") that somehow provides a loophole for all this.
But behave if you want to actually legally drive any of them.