Hmmm.

I definitely do see the concern with parents deciding to jump all over a teacher because their kid lied and got access they shouldn't.

I can see a couple ways to address it, but honestly, none of them really help, because all the kiddo has to do is wait until they get an invite code distribution (or hit up dw_codesharing if it has any) and create an account for themselves with a different birthday. A parent who was going to blame the teacher would still blame them at that point.