Hi! All we know about World Updates in advance would come from the developers (if they mention it - last time it was in the Q&A Twitch stream). Otherwise it comes from the Community Managers.
There are several areas in #self-service:wishlist for World Updates:
Search results for ‘world update category:163’ - Microsoft Flight Simulator Forums
If you post a wish in there, make sure one does not exist as we only want one topic per wish item.
There is one for Australia you can contribute and up vote on:
The Development Roadmap will show 4 months (1 previous - 1 current - 2 upcoming)