Could the Voynich Manuscript be a private educational system?

[ololololo]

[..]
At that time, there were no unexplored peoples in Europe that we did not know about. All, say, the Alpine "Indians" had disappeared by the beginning of the Middle Ages, long before VMS was written.

Maybe the question is not "which people do we not know / disappeared in late medieval",

maybe the question is "which people's medieval language do we not know / changed / disappeared meanwhile?"

The Prussians (not the later templars capturing that name) spoke a version of slavic.
The Livonians had an own writing system / alphabet and produced books, until they were conquered by the templars and their manuscripts were seized and burned.
...

That's true. But assuming such a scenario, we wonder what the scribe's idea was. If he wanted to tell us about the language or culture of these peoples, he would have written it in Latin. There is no need to go far - the Codex Barberini, a translation of the Aztec herbalist from Nahuatl into Latin, or the Codex Cumanicus, where the Kipchak words are transcribed into Latin and where it is marked that this is the "Tatar language". According to the logic of the VMS, they should not have been translated.
And any interpretation of everything contained in the VMS will be very far-fetched in this regard.