In a previous video on his original channel he talks about the first strike which was made against on of his tutorials by a company who published their tabs a few years AFTER he posted the video.
AIUI the point is that they're being indiscriminate by taking down the whole channel, including potentially both fair-use and non-fair-use items (and even original content).
I mean that sucks, but even without looking into the TOS this seems like the obvious result of any rule that involves multiple "strikes."