AC has made no push to retire the A330's nor have they said anything about it? It's a popular Anet assumption, which as per usual, is completely baseless. The a330's have started to be repainted into the new livery.
The A330s, as per the last investor day, are intended as "flex capacity". They are owned. They as well as the remaining 767s and 10 leased 777s (8 300s, two LRs) with lease terms expiring from 2019 to 2021 form capacity that can be rapidly shed in the event of an economic downturn.
There's been on-and-off talk about more 333s. It may make some sense to lease a few more. If demand remains firm all or part of them could be replaced by exercising more 787 options (most likely 9s, perhaps some 10s, 8s unlikely). I suppose based on the report one could see some 777s going out of the fleet and replaced with smaller 787-9s, or some 10s.
See: https://www.aircanada.com/content/dam/a ... y-2017.pdf