Pilots banned from Flight attendant jumpseats

I was surprised when I learned that CAL Pilots could not ride in their own flight attendant jumpseats. Yes, they would push back with empty seats leaving guys stranded. A CAL FA proudly explained to me that they got it in the FA contract that pilots can't ride in their seats since they can't ride in the cockpit.

So I am curious which airlines are like that, and which are like jet blue? Also did UAL's new TA(pilot) address this issue?