Depends who ended rulling A-H when all the dust settled, the issue is...when USGA was just one of the proposal give to Franz Fernindand(who he considered maybe useful but unworkable as he did not trust the magyar enough) the main idea was tryinng to curtain Magyar Magnates either via ausgleich or decret, the whole war would destroy the power of the romanian and strenght the magyar, and rudoplh was a defender of status quo, at long term i imagine Zita(who supported FF plans) might try via regency convice Otto to federalize or break magyar power once for all.
So i imagine a federal kingdom(imagine like germant worked but more along ethnic lines) but with a single, only Austrian(german) speaking army staffed with officer all the states, so nobody is loyal but to the Hasburg Crown.
Might work? depends, i think as their enemies are subdue and germany will support anything that end the post Franz Joseph mess.