An offer received through the ACU Guarantee scheme (similar to the WSU HSC True Reward scheme) is technically considered a conditional offer because students are still expected to sit their HSC exams, which constitutes the condition. Of course, this is not a complex requirement, especially since neither the resulting HSC marks nor the ATAR will matter, i.e. as long as you complete year 12 (irrespective of your results and ATAR), you are good to go.
Examples of early entry schemes where conditional offers of a stricter nature are made include SRS and SRS-based schemes. A good example of this is the UNSW Gateway Admission Pathway, whereby a successful applicant will receive an early conditional offer to their chosen degree with an ATAR entry requirement significantly lower than the advertised Lowest Selection Rank. There is also the need to place the chosen degree as the applicant's highest eligible preference in order for the conditional offer to become an unconditional one.
I hope this helps!