This whole topic seems ridiculous.
There are plenty of lounges to choose from at HKG, including two First lounges if you are a DM. I've never seen the Pier J get uncomfortably crowded, I'm sure Pier F almost never does.
I use Oneworld lounges at outports all the time, so I can hardly complain about other OWEs doing the same in HKG.
It's hard to begrudge CX doing anything that makes it an easy profit right now, especially given the amount they've invested in redeveloping lounges all over the world.
Of all the aspects of CX's operations, the lounges are the very last thing I'd be changing right now.