Originally Posted by sports1

Like others said, you will be rebooked onto another flight, most likely on AC metal, followed by *A metal, if your connection becomes at risk.

I've had 3 instances of IRROPS with AC since 2023 that involve rebooking of either the connecting leg or the original departing leg, and never have I once been able to successfully get an agent to book on non *A (ie. competitor's) metal. Most flat out just said "AC doesn't do that".