Nah, in that case (and I've had it happen to me where I DIDN'T make the flight because of this), the senior guy will get the jumpseat. If the back is full of revenue customers and you listed the day prior, checked in and everything, you could STILL not make it on if someone senior to you shows up for the jumpseat. We can't reserve jumpseats, so if the back is full, it's all seniority based. I agree with
@PhilosopherPilot . I like this system way better than the Delta/CAL/SWA systems I've been under before. I've never seen the senior guy NOT make it home.