I think this probably will be repeating my comments from a previous question.
I think it would be a fair concern for Claude, who runs generally speaking a very efficient operation that runs 24-7. If they are spotting traffic in Vancouver, and terminals choose not to unload those cars for a variety of reasons until the next day, or don't want to operate a shift, that has a significant knock-on effect in other parts of the supply chain.
If that's the nature of CN's concern, I think that is something that needs to be addressed with the terminal elevators. Given the situation we're in, in terms of the backlog and the pressures on the system to rebalance, I can't speak for those elevator companies, but I would imagine they will be operating every available shift, and frankly, I think they should be in order to assist the railways in reaching their objectives.