As Whopity explained, the means of supervision will have to be described in the ATO's documentation and approved by the competent authority. Continued approval will depend on compliance with the approved documentation. This is potentially more prescriptive than before as the competent authority is able to approve only the level and means of supervision that it finds acceptable.
Consequently, since approval will only be granted if the proposed supervisory process is acceptable to the competent authority, they would clearly prefer that there is no definition of 'supervision' in law. Such is the myth of a level playing field.