In terms of revenue generated, I'm pretty certain think a Diamond would trump any ID pax. Does this mean if, Y is overbooked and J is empty, the ID pax (who is standing by for Y) would be put into J first, before upgrading the DM?

IIRC, cabin crew don't have names of pax who are opup'd or on redemption. Has this changed recently? I don't recall seeing any lists of pax names other than the usual yellow sheet in the galley.

I hope this is just a cabin crew rumour, but having seen that CX staff are previously put on the opup list before OW elites and CX Silver, this could well be possible. The question remains though... where's the logic in this?