It's hard to imagine the Argos dumping Bourke if he lived up to the high expectations they had for him. It certainly wasn't a ratio move. Must have been related to (a) performance, (b) injuries, (c) salary cap, or (d) a younger player they liked better at the position.
Film review will tell our team's management if it's (a), and if it is I'm sure they will take a pass. If it's (b), one thing we know is that anyone who has ever been injury-prone only sees that problem get worse when they join the Ticats. We can manage (c), and (d) is an Argo-specific situation - I don't think O-line depth is a strength of ours.