The big problem with that _Phoenix, as discussed in another thread, at current oil prices the competition for CSeries is not only from the new MAX/neo but from older leases:
Bombardier Inc?s CSeries a tough sell as cheap oil revives used jet market | Financial Post
You're just not going to save enough $$$ from fuel efficiency to justify the total cost.
For many operators (especially if they already operate smaller craft from brand "A" or "B") the ROI for the CSeries is a very tough sell today vs. when oil was approaching $150/barrel.