Well, by Spring 1849 the Hungarians had the Austrians on the run. In fact by April virtually all of Hungary was liberated from Imperial forces, and Hungary declared independence. So they were very much in a position of power before the Russians intervened. Considering public order in Austria, I'm not so optimistic. In 1848, IIRC the uprising in Vienna started exactly due to the Hungarians defeating the Imperial forces and approaching Vienna. One wonders what could have happened if they actually take the city and the Habsburgs agree to reforms (at this point Hungarian independence was not a goal). But that's a POD for a different TL. Anyway, if the Hungarians continue their offensive towards Austria, we can assume that revolutionaries would take action again.