No, I would expect the resolution most favorable to the customer in either situation. If Coinbase had a public policy about what will happen in situations like this, I would expect them to follow their policy. Since they do not, it is reasonable to assume that any time they resolve a situation like this in their own favor they were using the customer's order as a free options contract.

I had Coinbase honor a price favorable to me after initially being declined, and have heard of the same thing happening to others.