If such an AI teacher style becomes widespread, this means that they have the potential to replace the parental relationship (in the same manner AI girlfriend/boyfriends threaten romantic relationships).
I see people talk about the dangers of the AI girlfriend/boyfriend, but not the dangers of introducing AI teachers to (especially young) kids. Nominal adults are already being affected by this (see Replika and company) and they are not even the "best".
If I wear my cynical hat for a second, I'm willing to bet that this parental replacement is a certainty, as an extension of the "screen" parenting that already exists. But this time, it might actually be helpful for the child so it will be socially acceptable and encouraged.