That’s a fair breakdown of who is commercially affected (though not always accurate), but my original question wasn’t about impact — it was about whether oneworld Emerald lounge entitlement can legitimately be constrained by a Cathay membership T&C or system design. That part still seems unresolved.

For example, a Cathay Silver or Gold member who holds Emerald status with another oneworld airline is affected. A Cathay Diamond member crediting flights elsewhere during renewal is also affected.

Point 4 assumes that a forced choice between alliance status benefits and Asia Miles earning is legitimate, but it never explains why such a trade-off should exist. Under oneworld design, status benefits and earning choice are intended to be independent.

Point 6 conflates discretionary benefits with guaranteed entitlements. Operational upgrades are discretionary, whereas lounge access is a defined alliance benefit. Preventing gaming of op-ups does not justify constraining lounge access. These are two different benefit types, and mixing them together does not justify a blanket restriction.