MRJ is already affecting sales:
1. Scope clause is primarily for US regionals only. Around 100 of MRJ's orders are from outside of the US. That's 100 sales to a segment previously dominated by the CRJ.
2. Even in the US, SkyWest and TSA have ordered 150 MRJs instead of CRJs. And they are still holding on to those orders -- hoping for scope changes -- so effectively they are lost sales to Bombardier.
Unless (and until) Bombardier has an appetite to re-engine the CRJ, the RJ market segment will get dominated by E2 and MRJ in the future.