Quick question: AC seems to be really good with tracking flights and pro-active rebooking (at least for SE's) ones you started your trip (say you are in the air and they realize you won't make a connection). However, they seems to be very reluctant to rebook in advance.

Today, I will likely miss my connection in YYC. There are several options to be rebooked me to get me to my final destination including two flights on AC metal (and yes, there is space available). However, the concierge insists I go to YYC first and they will take care of things should I actually miss my connection (which may mean I spend the night in YYC and get to the final destination a full day later…). This happened to me at least twice before. Why does AC seem to be adamant about proactively rebooking prior to starting your trip?