One of Bombardier's problems focusing on the C Series is that they've effectively neglected the CRJ, conceding the regional market to Embraer and newcomer Mitsubishi.
They've ceded the upper end of the market, 70-76 seats. In other words the one artificially limited by scope in many of the larger markets.
SkyWest has made no bones about it that refleeting is a priority. They've also made it clear that the 50 seat market isn't as dead as others have predicted. This evidenced by them pulling cheap 50 seat CRJ-200s out of the desert.
Not implying BA is going to build more CRJ 50 seaters, but that replacement is going to have to come from somewhere. Where I don't think is the solution will be larger aircraft with lesser frequency as predicted, though it will be a player.
Maybe a new new NG Q?