Yep! You never know what might happen at the end of the year.
In fact, it's compulsory.
I think J41's trying to say that you have to go if you're well enough to be at school that day and you can't skip it simply because you felt like it.
Really? I was able to get out of the GAT this year due to illness. So I as worrying if it will affect my end results?
I still plan to do it next year though.
I was sick with a fever and a bunch of nasty symptoms the day of the GAT back in Year 11, while I was doing U3/4 Psych. While they did state that it was unusual I was away for the GAT on my transcripts (saying something about being results being unavailable for illegitimate reasons or something), despite the fact that I did produce a medical certificate to my school and assumed VCAA would've had that on their records, there wasn't any effect as I was present for my end of year Psych U3/4 exam. Basically, VCAA'll think it odd, but you won't be in huge trouble, as long as you sit the final exam (although, if you have a bad day on the exam day, uh...).
Having said that though, if you are to do the GAT and are relatively well enough to do it, then please give it your best shot anyway. Having
a safeguard is a lot better than going in with only one shot to make things go the way you want them to. (Basically, take the GAT seriously, please.)
Side note:
Here's a brochure for this year's GAT.