There is no move to get rid of the Linux Australia brand (15-odd years old right now) and the linux.org.au domain. These are deemed to be far too valuable.
Then why change? The organisation has now expanded its activities - it sponsors conferences on other open source topic - Python, Drupal and WordPress as of this year.
It also backs other organisations, like The Ada Initiative, which are involved in activities that it believes come within its remit as an organisation devoted to free and open source software.
And it also has no intention of changing the name of its best brand - linux.conf.au, the name for the Australian national Linux conference that is known worldwide for being one of the better conferences of its kind.
While a number of names have been suggested, one of the problems is that many of them - or many similar-sounding names - have already been taken. For example, a suggestion to change the name to Open Source Australia was made but the acronym OSA is far too much like OSIA - the acronym for Open Source Industry Australia, which already exists. (Suggestions can be made here.)