Suppose that Austria still had a few bucks left after losing the Austro-Prussian war and losing Germany made them mad enough to take their frustration out on Hungary. And let's say that the next 50 years survive the ensuing butterfly attack, and by the close of 1918 Austria is on the losing end of World War One.
Does Hungary get a better deal if their name isn't on the mailbox? They may not have to worry about armed forces limits, and reparations. But Yugoslavia, Czechoslovakia, and Romania all have territorial claims on Hungarian lands that the allies might agree to.
What, if anything, changes if Hungary is invaded after the war? Do the allies intervene? And how will the Hungarians react if they consider themselves a freed people and they still get screwed over?