The disconnect over the Rowling thing (and all trans issues) stems from the fact that most people don't disagree with what she is saying, and I'm sure that'd be a similar phenomenon with the long video if anyone ends up watching it. 3 hours of "Rowling said this" and the reaction wouldn't be that they don't believe she said it, but rather that they don't think what she said is wrong. The left is delusional about this and seems to think that what it calls "Trans rights" are as settled of a moral issue as interracial marriage or letting women vote. Then they act incredulous when people say they don't like the idea of giving kids chemical castration drugs when they say they believe they're trapped in the wrong body. and their incredulity makes the left look even more out of touch, and the genocide claims end up looking downright unhinged.
Without having watched it I would assume most of the video is "Rowling liked a tweet by this person, here's a 20 minute segment on why that person is pure evil". There's just no way you can come up with 3.5 hours of content about Rowling's trans views alone, and a lot of the anti-Rowling discourse follows this pattern of bigotry by association.
Yeah, so much of it revolving around social media and Twitter specifically is another part of the disconnect.