Where do the regulations say non-expired ID? Can you refer to a Transport Canada source where it mentions non-expired ID is not valid. The regulations I see are only reference to Government issued ID and reference Drivers license as an example. Also the AC website does not mention anything about the unacceptable ID if expired.

The WS website appears to be the only place where expired ID is noted as unacceptable.

The USA has better no fly list redress and acceptable id policies because this was considered a news event that hit some metro areas local news on a weekly basis. Therefore I submit that more news stories are needed to prod the government into action.

Ultimately there needs to be a companion process for travelling without Id but where the airline can vouch for at least some part of your identity. My suggestion would be to have a full security investigation (eg SSSS) for these instances.