"I am confused with the article though. What would have been a successful result? That the all canceled currencies wouldn't have been exchanged or deposited?"

"I am confused with the article though. What would have been a successful result? That the all canceled currencies wouldn't have been exchanged or deposited?" Yes - exactly - the assumption earlier was that a significant amount of money stored with the denominations that were de-monetised was "black"/unaccounted money. And this would not be deposited into banks due to fear of being scrutinized. If this had happened on a large scale and if the money had not been deposited - the liability of the exchequer would have reduced.