Now that literally made me laugh out loud...have you read the Terms and Conditions that you agreed to when you signed up for Aeroplan?

Let me summarize; they make the rules, they are free to change the rules as they see fit at any time without obligation or penalty, and oh btw sucks to be you, if you don't like it, don't play the game.

You, we, whomever, may not like the changes but they are fully in AC's purview to make and there is no legal obligation to you or anyone that they are violating.