There was no incentive for them to mess around with the occupation zones from OTL. If you look at the map then you'll see that the French and American occupation zones in Germany and Austria are contiguous and the Russia zone borders the east.
Well, different plans for the division of Germany may easily be concocted by the Allies if they don't care about giving Austria a break or see it as something separate. There is the traditional Nord-South division of Germany at the Main, which has a strong precedent. The allies may plan for dividing Grossdeutchsland into North and South Germany (if they are still in a collaborative mode) or a British Northwest, a Soviet Northeast, and an American South, including Austria (with or without Russia keeping East Austria). When Cold War starts and Allied cooperation about the future settlement of Germany breaks down, this would default to West Grossdeutchsland and East Grossdeutchsland as usual.
As soon as Cold War starts, those issues become wholly secondary in the minds of the Americans and the Soviets. The Western mantra becomes "keeping the Americans in, the Soviets out, and the Germans down", which can be done easily as long as the Western powers keep troops in Germany and the countrey politically bound to the aborning EU/NATO framework. as soon as 1950, America was quite eager to rearm Germany. If the conditions to set up Austria as a separate state are butterflied away up to then, or conversely, the conditions to divide it like the rest of Germany are butterflied in (see my preferred PoD about a communist takeover of East Austria), a separate independent state of Austria shall never be born again.