Sounds like you know it all. Why should our name be derived from the Latin?
People pushing for a different date for Australia day do so because they see that date as an invasion. If so wouldn't an aboriginal name be more appropriate?
A few decades ago a late night jockey on radio might have mentioned a flag change and being laughed at.
But......
Indonesia, Zimbabwe, Sri Lanka, Vietnam, Bangladesh, Formosa etc, etc.
Certainly could see states being renamed. Not saying Australia will change its name for sure but it may be proposed.
Not impossible with numerous precedents especially following the rejection of colonisation and occupation which is how white settlement is increasingly seen as.