This happened to Laowhy86 too. If you're not familiar with him, he's an American vlogger living in China. Most of his videos are him talking about China, a fair number of them include his wife, and a few include his baby daughter.
The videos that include his daughter are totally innocuous and her presence is usually a brief cameo. Well because his daughter appears in a few of his videos, Youtube got rid of the comment sections of every one of his videos.
The stated reason Youtube has given for doing this is some people have been leaving inappropriate comments on videos that feature children. Well if someone's leaving inappropriate comments, aren't THEY the problem? Shouldn't Youtube be going after THEM? And if Youtube is going to get rid of comment sections on videos that feature children, why get rid of the comment sections on other videos from the same creator which don't feature children?
Youtube's response seems like an unjust and heavy-handed way of addressing the problem.