[rmccue]

It appears this is functionality provided by YouTube themselves where you can set a CNAME: https://support.google.com/a/answer/6214622?hl=en#zippy=%2Co...

[helb]

thanks, looks like you're right:

    $ kdig +tls www.youtube.com @kids.dns0.eu
    …
    ;; QUESTION SECTION:
    ;; www.youtube.com.      IN A

    ;; ANSWER SECTION:
    www.youtube.com.              300  IN CNAME restrictmoderate.youtube.com.
    restrictmoderate.youtube.com. 1611 IN A     216.239.38.119