I cannot help you with Asia Miles, as I do not use them.
As very few people fly CX nowadays and visit the CX forum, it might take time to get answer.
Two general points:
1. Given CX sore state, it is a pure guess what they will operate in 2023. The HK covid restrictions might (just might) improve and they will resume flying to ZRH (for the ZRH-SYD). But it is far too early to tell. Planning something for 2023, including a cruise, is kind of heroic.
2. I have extensive experience on BA. I don't think that you should treat award availability on EZE-LHR-ZRH as the availability of two separate segments. I often had availability on HKG-LHR but no availability on HKG-LHR-EU, although both segments have availability. I assume the same will happen for BA awards on AM.