Yes it is a completely new topic, but:
Provision of free flight tests is not a no income, but nil cost, nice gesture.
As a minimum the ATO would have the loss of the cost of fuel used and, unless the Examiner is an employee of the ATO on a salary independent of flying time then, either the ATO or the Examiner has the loss of the Examination fee.
Not many ATOs would provide any free Renewals/Revalidations to their Instructors and, in the case you outline, there is absolutely no business reason for them to provide a free IR Renewal to you.
If you are an employee of the ATO then look at your Contract of Employment to see what you are entitled to, or what the ATO (at their own discretion) may provide.
Most would probably give a reduced aircraft rental rate to their Instructors.