SIA already starts (as usual) to put 744s on sale. 9V-SMD will be leased to Air Nigeria obviously.
In general I think its pretty early (and the wrong point in time) to replace the 744, the oldest are 13 years old. LH and JAL certainly won´t, BA might be forced economically, UA certainly. SIA, and less so CX are known of having a young fleet, so they´ll start first.
On the other hand Emirates for example already announced that they´ll start replacing 777s (with newer 777s)
Btw you forgot Lufthansa, they almost have twice as many 744s as CX does.