Nationalism was not yet a conservative position at that point. At least not in the Austro-Hungarian Empire.You are in fact forgetting that nationalism in the third world was not a conservative position even just a few decades ago!

Toppling the old Empires in order to enable self-determination of nations, was a radical idea and indeed a push for global change.

Also note that I'm talking about conservatives here, not right wingers. I don't know why you seem to think otherwise but the right wing has had plenty of people one could describe as:

Naive young men who wanted to throw out musty old books and change everything for the better?

Fascists for a start.