With other divisions increasing revenues amid healthy margins, the loss-making Commercial Aircraft's time was up. It's future hope, the CSeries, was digging an ever deeper cost hole with each delay. Only a market success could save it.
The Boeing trade complaint in April 2017 made a success far-fetched, sealing the fate not only for the CSeries but for the Commercial Aircraft division.
With the CSeries at Airbus and Q400 at Viking Air, why keep the CRJ? It makes no sense. The CRJ is presently dressed for sale. Now it's more a question to whom and when.