Tbh I wondered why they hadn't done this a long time ago, although this seems a cackhanded way to do it, rather than a phasing.
I spent a year or two of my life working on the 4 P&O Hull to Amsterdam/Belgium ferries. Thought it was curious that one had English crew, all the rest were cheaper Filipino or Portuguese crew. They also all had Dutch officers and staff.
It may be shitty but a lot of ship crew on plenty of other lines and the cruise ships are made up of cheaper overseas labour.
FWIW the Filipinos were the best people I'd ever met. Ma mi miss kita, pinai ako.