You would need to inform immigration once the relationship ends in writing. After that, they decide what to do from there but don't expect to be kept in the know as it no longer pertains to you. As far as the divorce goes, you handle that separately.
https://www.homeaffairs.gov.au/trav...grant)-visa-(subclass-100)-document-checklist
https://www.homeaffairs.gov.au/trav...grant)-visa-(subclass-100)-document-checklist