Anyone who believes that airlines will make a commercial decision of this kind with any regard to what the pilots think or want is delusional.
I suspect that you have mis-read the posts on this thread. Pilots know that they are not in a position to make decisions about aircraft acquisitions, they are merely speculating about what decisions management will make and
WHY!
Commercial decisions are never straight-forward and are influenced by many factors such as politics and "loss of face". Selection of the A319 over the C series may look good in the short term but would look poor as fuel prices increase over the service life of the aircraft.