I think the “operational spare” is a good move.
In reality, this means they are operating the fleet less tightly scheduled, which is good as recovery of a full A380 is very challenging as you’d need 2 787s to cover it, and/or cop a massive delay(s) sometimes for days whilst the issue is resolved. I assume this will done be extended downtime at either SYD (most likely) or LAX. Those on the forum who are schedule gurus will probably have a decent idea on that aspect.
You’ll recall the publicity they got the last couple of christmases when A380 diverted to Baku, and had operational issues (delays) and a lot of bad press for disrupting Xmas travel so no doubt that factored into the late 2025 planning. Whether they stick with this plan long term, or get tempted into other routes / higher utilisation in the new year, who knows.