So, assume that the Central Powers win WWI.
How likely would it be for the Austro-Hungarian Empire to annex Serbia (minus Macedonia) and Romania? And perhaps also Montenegro? Did the austro-hungarian leadership consider such actions?
For what reason would they do such? To remove outside actors from interfering with ethnic minorities within Austria-Hungary? For resources, given that Serbia had food and Romania had oil and the mouth of the Danube?
Would holding such regions be feasible for Austria-Hungary in the short term?