Wait, I never said that the Austrians took Sicily, what I ment to say was that if the Central Powers were to win the war, then Austria would gain Sicily as a reward.
And nobody in Wien or Budapest was crazy enough to even think about something like that.
The empire had already too much minority; adding more italians will have only caused too much troubles; hell, even trying to absorb Serbia was considered too far fetched and somekind of puppetization though as more pratical.
At most A-H want reparations and border adjustment favorable to them in term of defense.