John Gissing has openly said that management are not interested in the C Series. The delayed certification, untested technology and the fact an engine went boom on a test aircraft earlier this year has not made Qantas want to put any ships on the order books with Bombardier.
A319/318 on the other hand...
Or even the Embraer E2...
But honestly I would bet the house that even they don't know what they want to do for a 717 replacement. So a C Series order is unlikely, but not impossible.
Fuel-Off