Yep. For reasons of propriety, for one thing. But also because the data protection laws get especially opinionated about what you do with kids’ speech, and one line they draw is at age 13. The American variant, COPPA, dates back to 2000, and requires verifiable parental consent to process the data of under-13s.
No idea if that matters retrospectively in legal terms—it’s seems to me that the main problem was providing service to the kids in the first place—but it’s icky either way. Then again there’s an ickiness to the entire project of pretending casual users’ arcane permissions settings from 15 years ago indicate affirmative consent today…