For CX450, the flight continue to NRT. CX might block some seats for passenger boarding at TPE. Another reason is CX only open OLCI 48 hours before the flight depart, most of the seats will be unblock when OLCI open. (Except bassinet & exitrow)

Besides Bassinet & exitrow seat, CX also blocked some seat for crew rest. Such as, 80K in 74A, 12K & 67-69 HK in 33B. (Long Haul & Australia Flight) Those seats are impossible to get except 67-69HK. They will use it when Y is completely full.