The published deadline is October 15. That means: the flight that takes you over a threshold needs to depart on or before October 15. There are anecdotal stories about the possibility of a later, internal, unpublished deadline that Aeroplan uses, but October 15 is the official date. Neither Air Canada nor Aeroplan is going to tell you in advance about a later unpublished deadline. We on Flyertalk cannot possibly know for sure one way or another. The only 100% guaranteed way to get early recognition is to meet the deadline. The choice to reroute a current booking for more miles, or even to book a true mileage run just to meet the deadline, is entirely up to you.