Embraer and Boeing are smiling either way.
A big factor right now is the relatively low cost of fuel. If you're already a large E175 customer, the higher initial cost of the E2 version might not compensate for the per trip cost savings from better fuel efficiency. (KLM doesn't own any E195s so buying 195-E2 makes sense for them).
The CSeries / A220 is in a worse position in this respect, since it was designed when Bombardier was projecting oil price going to $150/barrel in their business case. That justified a much more expensive clean-sheet aircraft as long as it's fuel efficient compared to the current fleet. But oil today is closer to $60 than to $150, and Bombardier -- having placed the wrong bet -- is likely mere days away from exiting the commercial aircraft business.