I have no direct knowledge of YouTube's configuration, but my more general knowledge of how Alphabet does business suggests that high-business-value customers have company-internal guardians (in sales, advertising, or biz-dev) who are actually tasked with making sure nothing breaks on their services. I assume they do the same for high-biz-value channels, so I'd expect fewer accidents on bigger channels with more opportunity to make a mess for YT than smaller ones.