No it wasn't
Austria also should be totally separate from Hungary
Hungary's greatest power was in the 12-15th century, dominating all the surrounding nations. Including Austria
On the attached map:
Blue border is Louis I's realm, while the pink border is Matthias Corvinus' realm
The pink territory is the core kingdom of Hungary, more or less continously ruling over all those southern Banats (including northern Serbia, Bosnia and western Wallachia), the Banats of Ozora, Só, Macsó and Severin for more than 300 years