You see, you are trying to make logical sense of a propagadanda hit piece that was designed to appeal to emotions, which is why it looks ridiculous when you analyze it that way.
The narrative is designed to invoke an image of those old schools you see in movie or something, where the pupils are slapped if they dared to use their left hand to write, and speak in their local dialect or something like that. So in other words, pretty oppressive sh*t. As for the adults, it's the old editing tricks that evokes images of "Konzentrationslager" with "Arbeit macht frei" as theme (i.e. vocation training).
Put together, it is meant to evoke an emotional response to the effect of "ZOMG the ebil Han-supremacist SeeSeePee is actively genociding the $LOCAL_MINORITY in $CURRENT_YEAR!!1!!1!". You were not meant to think about it too hard, because then the narrative will fall apart. And if the narrative gets planted into people's head first, it is very hard to displace it, because evidences to the contrary can always explained away somehow. After all, I, too, believe that Bielefeld is fake news
Now for my hot take: "cultural genocide", when taken to its logical conclusion, includes standardized education. Think about it, a standardized education is meant to take someone, strip them of local cultural context (aka family), and mold them into a standardized worker. Even if there was no overt effort to suppress any local language, the fact that education materials are written in a standardized language and not the local one and that the educations are more often than not delivered in standardized language, meant that the local language (dialect, accent, whatever) will eventually be displaced.
This is why the whole "cultural genocide" thing is useless, because a lot of fairly mundane things can be thought of as such to the point where it dilutes the actual term "genocide".