They release the cut-offs after the offers have been made as until they have made the offers they don't know.
The cut-offs are determined first but after the offers are made e.g. if there are 100 places in a course and last year the 100th person had an atar of 89.5then the cut-off released was 89.5 but this year to fill those same 100 places the cut-off might be 88.5 so that will be the released cut-off. If the 100th person though has an atar of 93.5 then that will become the official cut-off.
I have know a cut-off to move by over 20 points within a two year period (my godson needed 88.5 to get into a course after he finished Year 12 but he didn't quite get it so went to TAFE for two years and then applied again using his 87.0 atar only to find that the cut-off had dropped t 66.3 and so he was in with not trouble at all.)