No, you misunderstand. In 80 years before or since, these dozen or so ethnically Jewish scientists were literally the only world-leading Hungarian scientists. (Maybe I would add Eotvos and Szenty-Gyorgyi, but that’s about it…)

Given that only 5% of the pre-WW2 population of Hungary was Jewish, the fact that 80% of geniuses were of Jewish parentage is highly unusual, emigration or not.