That's my reading of it too, it's all a bit confusing really.
If you actually enter to G2G application process, there is a link to the Medical Emergency order
(here) that includes the following. Perhaps read example 3.
Persons otherwise approved on any other grounds, including other compassionate grounds (r) any person or category of person who I as the State Emergency Coordinator, or a person authorised by me as the State Emergency Coordinator for the purpose, approves in writing and who complies with any terms or conditions to which that approval is subject (which may include a quarantine direction), whether on any other compassionate grounds or on any other ground whatsoever. Note: this provision for approving persons or categories of persons is intended to ensure that where a person or category of person is not provided/or, either generally or in a particular case, consideration can be given to whether entry should be permitted and, /{so, on what terms (such as airline or maritime crews or persons wishing to enter Western Australia for work-related reasons not captured above). Consideration will be given on a case-by-case basis and evidence may be required, such as a medical certificate. Example 1: a person may face exceptional hardship if they are not permitted to enter Western Australia because they live in Western Australia and operate a small business and would face financial ruin if they were prevented from entering the State to return home and operate the business. In such a case, approval might be given under this provision, subject to a quarantine direction and possibly other terms and conditions. Example 2: a person may be entering Western Australia to comply with a court order and it is impossible to comply with the court order and a quarantine direction. In such a case, approval might be given under this provision and again may be made subject to other terms and conditions. Example 3: a person who was in casual or other employment and living in Sydney needs to enter Western Australia because they have lost their job, have no means of support and will need to live with and be supported by their family until their circumstances change. In such a case, approval might be given under this provision, subject to a quarantine direction and possibly other terms and conditions
If you were granted access and a citizen and owned a home or a relative that owned a home you would be staying at, then I suspect you will be in home isolation.
Most of what I've read applies to people moving around AU, not returning from O/S