I find it hard to believe that Delta (or any other major airline) wouldn't reciprocate. When I got rebooked onto an Alaska flight, the gate agents were openly

I find it hard to believe that Delta (or any other major airline) wouldn't reciprocate. When I got rebooked onto an Alaska flight, the gate agents were openly annoyed at having to accommodate Delta passengers. However, the relationship between Alaska and Delta has grown more adversarial so who knows. I should also add that a few years back when my Southwest flight out of SFO got cancelled I was able to book a seat on a flight out of OAK with a minimum of effort. I think I had to pay the difference in fare though. When it works, it works, but the go it alone attitude will only take you so far.