Yes, that question covers a number of aspects.
At the moment, we're unable to contact Canadians abroad directly, in part because we don't know who they are. Some of them register with Global Affairs Canada, but many Canadians living abroad aren't in contact with us. We don't even know if they're in the country or not, so it would be very hard to contact them directly.
What we post on the embassy website or social media is written in such a way as to encourage Canadians to vote and to register on the voters list. We do everything we can with the resources we have to communicate when there's an upcoming election and provide instructions for registering to vote.