More flight consolidation it seems...
Was booked LHR - HKG - AKL on CX254 and CX113 in J on March 19th.
Got an email last night cancelling those flights and offering the alternative, still on March 19th, on CX252 and CX2191 instead. Which is a perfectly fine option for me, with the minor annoyance of quite a long wait for my domestic connection in AKL (maybe I can get something earlier).
It is interesting that I now don't have a seat assigned for LHR - HKG and if I try to select a seat on the website I get "Seat selection is not available at this moment. Please contact the operating carrier for further arrangement. [E21O3117]".