This has always been my one bone of contention with what is otherwise a superb airline; they made a real pig's ear of the whole PTV issue, fitting them to the 747 Classics (which were subsequently retired) before the -400s. However, it should all be done by now.
The only fleet not so equipped is the 772*, because it was expected that this aircraft would leave the fleet. However, this possibility must now have faded, given that the first 777 is to join the CX fleet. I would expect the 772s to be PTV equipped in due course and 777 #1 should be PTV equipped when delivered.
(*oh, I forgot the ex CA A340s, but they should not be with CX for too much longer. Rumour has it that they're returning to CA).