On the LAX-HKG-LAX (and on to MNL) on the 777W 4 class, all seats on the mini cabins appear now blocked. I purchase Business class fares (sometimes I class, other times D or J).
For years I had no problem selecting the mini-cabin 11A or K or 12 A or K if unoccupied at the time of booking. I was Gold, then Diamond for many years and back to Gold due to less need to travel, but still the seats were available.
As a gold it appears the seats are no longer available for selecting them. Calling CX, the experience is varied, sometimes an agent or supervisor will release the seat to a Gold, sometimes they refuse, even when all 8 seats are blocked and unoccupied - like months ahead.

Twice they lost the sale of the ticket (flying LAX-MNL) as I chose a ROOM window seat on ANA instead, (would have taken CX if my preferred seats were selectable, even at a higher fare).

Granted, I understand Diamonds have some privileges, and other airlines also block seats for top elites. However others, if you pay full fare Biz they usually let you choose any open seat (or British would charge some extra).
Since I will not likely make Diamond, and Gold has no perceptible value if purchasing business fares, I have multiple choices on the route. Being able to select my preferred seats kept me choosing CX - with this off the table, I can save a few dollars and fly on ANA via HND or UAL Polaris via SFO.

Anyone knows if there is a clear policy on these seats on CX?

Sorry to hear 0293.hk dropped 1.5% today cause they lost out on a MNL fare.

From my experience, those are generally not blocked off to Diamonds. Recently flew from LHR-HKG on J. Was looking to change my flight from CX254 to CX252, and was able to see that all window seats were available in the mini cabin on the CX252. Unfortunately, wasn't able to change my flight, but I was able to reserve 12D on CX254 well before the date of travel. I only have CX silver status.

NH Room is much nicer than CX J seats anyway and better food too.

I know that hardly any one customer affects the performance (they have much bigger problems than loosing a couple of tickets from me and my company)
I simply was pointing out how a policy of seat blocking affects some flyer decisions.

That was my experience for years, Tried to book a September itinerary and a December itinerary, and both had the mini cabins blocked to golds on both directions (they would release to Diamond but not Gold). Since I purchase fully refundable fares, for now I booked on another carrier.
Will check later or a different agent if they open up.

Yes the NH Room is a great seat - currently not offered out of LAX - but did flew a few times last year. The food, not so sure.
Will see how it compares to the Aria once deployed.

Did the agent explicitly state that they were blocked for DMs?

recent I class

777ER mini cabin blocked for OWE.

life was too short to chase them or ask for release.

besides i hope they can just fly on tIme like SQ. my hkg-syd yesterday delayed by 1.5hr total crook show

Yes he did, in my case.

I for one greatly appreciate that CX is doing this. There are many DM or above that book last minute and on the 77W being in 11A/K results in a much quieter flight and a better sleeping surface with wider footwells. Both BA and SQ do the same thing for their DM equivalents. It's not nice to be paying a last minute walkup fare on an overnight flight and being stuck in a middle seat towards the back of the second cabin or 15A which is basically halfway in the galley.

If the seats are unassigned anyone can ask to be moved at checkin.

One must remember that due to CX generosity, there are a truckload of 840 pointer DMs out there to fight for the same seats

This made me curious. Is the number of Cathay members published? Like how many SL,GO,DMs?

this number is irrelevant. Only the DMP population is published in percentages.

BA does not do this in J, only in F.