I can't see this happening any time soon.
First the Government of Canada would have to convince every bank to drop all fees for debit card use, and that will never happen.
Passing Legislation to eliminate cash would guarantee that the governing Party was ousted in the next election. A lot of the Seniors and low income demographics use cash almost exclusively for any purchases made in person.
I only use cash, unless I'm buying something online. Every five weeks or so, I withdraw enough cash to last me for five weeks, so I never pay any service charges. I know several small businesses that don't charge HST when payments are made in cash. Rather than generating large new amounts of tax revenue, eliminating cash would just lead to large scale bartering. The biggest losers in this scenario is the young demographic, who tend to spend their discretionary income on things which have no value in the secondary market, like new clothing, food delivery, vacations and products shaped like unicorns. When THEY get old, they'll find that they don't own anything which has any value to someone else.
If and when this did happen, I can foresee large scale cyber attacks from one or more of the Eurasian superpowers that could effectively bring much of the economy to a standstill, if only temporarily.
This sort of thing usually precedes massive inflation, (similar to what happened in Zimbabwe). which was
11.2 Million per cent for a month in 2008. That would decimate any Government or private pension plan which has guaranteed cost of living increases written into their plan documents.
The USA would never go along with this, so Canada would kiss goodbye more than three-quarters of its non-resident tourist dollars. Those over age 65 don't contribute nearly enough to the economy any more, compared to what they drain from it, but they are one demographic from which the percentage who vote in elections is very high.