Not really, I restarted maybe 4-5 times until they did Balanced Budget, saved the game and created a copy. This way, if I need to restart, I can just go with A-H Hungary right off the bat.
They don't have to, but for the reason mentioned above, it is easier to to do it this way (so that you can redo the entire playthrough with Hungary still being locked into A-H tree. Also, I think it's better if they flip and get the Czechs ASAP for my approach to work, so that they have them before Sudeten and also take advantage of all of the new industry and cores to prepare for war.