They don't need chromebooks in schools, my kid uses YouTube kids at home (that doesn't include shorts), teens will have their own phone usually, and youtube is already a popular place for them to go, discovering YouTube shorts (if they haven't already), is easy.

But ya, if a teen is otherwise cut off from devices besides the ones they get from school, then you could see that as a weak point, although I don't think that applies to a significant portion of families. For the ones that it does apply to, they probably have bigger problems to worry about than TikTok being banned.

The admins should be able to block YouTube for minors when asked. There's a way to do it but it's by OU not individual user. Fight for it if you want it.