Well do you believe schools in the US should teach all classes in Spanish or other foreign languages? Or should students learn the language of the country they live in? That's the "controversy" in Ukraine. Hungary wants schools in Ukraine, to teach only in Hungarian.
Does Hungary allow schools to teach their students in any language they want? Or does Hungary maintain that students must be taught in Hungarian?
The surest way to Balkanization and disintegration is to not have a nationally recognized common language, and that language should be the language of government and education. People should be free to speak whatever the hell language they want at home, or among themselves. There is no unity in division.
I found this: Schools and Education for Expats in Hungary.
“The official language of instruction in Hungary is Magyar (Hungarian), which tends to dissuade many expats from enrolling their children in the public education system. Some public schools do offer extra Hungarian language classes for foreigners, but this is at the school’s discretion and little further assistance can be expected.”
Sounds like Hungary is accusing Ukraine of doing that which Hungary itself does.