Just a heads up...no one is going to get denied...but I know most captains will make sure the appropriate priority is followed. A computer doesn't determine who rides in the cockpit...the captain does. The only thing that computer is used for is to ensure you're eligible to sit up there...it's not a promise that you'll make it.
I'm pretty sure UAL pilots would raise all holy hell if UAX pilots where bumping them off of their aircraft. So when the regional's raise a stink, it's "childish". When mainline does it, it's "solidarity". Mainline guys haven't gotten anything right since the 90's and this one is no different. Enjoy it guys.