op-up when cabin's not full
I've just got op-uped to J from PEY last night HKG-SYD. Received email from expertflyer about seat change at -2 hours. However, it still shows as 8J 1W 9Y at -1 hour, and there are still 2 seats empty (unselected) at PEY section.
Is this a normal practise for CX to op-up someone so they can free 1 seat at the lower cabin just in case?