Tho I wouldn't compare crusading in Balkans with creation of Crusader states in East:
a) the state Władysław ruled over (Hungary) tried to exert it's influence towards Balkans numerous times, he even had "king of Bulgaria and Rascia (Serbia)" as one of his regnal titles so why wouldn't he want to actually excert his sovereignty over them if he could? Most likely Serbia and Bulgaria would be governed like Croatia was - parts of Hungary with considerable autonomy, but overall joined to Hungarian crown.
b) the second state Władysław ruled over (Poland) had actually common ancestry (Balkans were at that time mostly inhabited by Slavs) with most of people Władysław would be ruling over and what's more important, according to Italian chronicler Kallimach, they still somewhat cared about it, because they recognized similarities in language and that common ancestry (p. 30 of that text -
https://www.academia.edu/12967498/Świadomość_wspólnoty_słowiańskiej_w_pełnym_i_późnym_średniowieczu, there is written in Polish: "Kallimach, opisując zwycięską wyprawę antyturecką 1443 roku, upatrywał źródła jej sukcesów między innymi w tym, że Bułgarzy chętnie poddawali swoje miasta królowi Władysławowi ze względu na podobieństwo języków i wspólne z Polakami pochodzenie", in English: "Kallimach, while describing victorious anti-Turkish military operation of 1443, seemed to think that it's success was caused partially by Bulgarians eagerly surrendering their cities to king Władysław because of similarities between Polish and Bulgarian language and sharing ancestry with Poles"
c) Balkans border Hungary, crusader states in Levant didn't share border with any Christian country.