should the domestic sector even waitlist for domestic first?
i suppose some I fare international would also have no I space in domestic sector and booked into economy. should they also allowed to be upgrade when I class open up?
If U space opens up, then call and pay a change fee (if applicable) to change. otherwise, it seems that to waitlist someone no status in Y for J as displaced passengers is wrong because there could have many other displaced passengers even in revenue fare class