The same will happen with the C Series - it will fill a significant gap between 100 seats and 150 seats.
100 - 130 seats will be fought over by Bombardier with the CRJ1000, CS100 and CS300, by Embraer with the E190-E2 and E195-E2, Mitsubishi with the MRJ90 and, eventually, MRJ100, and Sukhoi with the SSJ100. From 130 seats up there's the Airbus A319neo and Boeing 737-7MAX. There is no gap. Airbus were stringing Bombardier along and now know everything they need to know about the C Series. The C Series is, technically, a fine aircraft but Bombardier will never be able to compete on price with Airbus or Boeing. Already deals are being done where the A320 - never mind the A319 - is being priced less than the C Series.
If they'd launched a "CS500" variant with 150 two class seats from day one they might have picked up some volume orders and gained economies of scale but it's too late now.