I'm pretty sure their entire statement was full of lies. Especially the part where they said this isn't because of the Twitter mob. Like you (and others) have said, they did this on the flimsiest fucking evidence. It's clear they were just itching to pull the trigger.
What I think really did it is that the tech industry is controlled by the progressive furry LGBTQ+ twitter pronoun crew, from the bottom-up, and they call the shots now. This applies even more so in the infosec community, which has been thoroughly subverted with this type of bullshit. And that's CloudFlare's primary market.
For every Matthew Prince that may believe in neutral/libertarian principles, you have a dozen people under him (or purchasing from him), from a newer era, who are SUBSTANTIALLY less gung-ho about freedom of speech and information than those of us who enjoyed the wild OG Web 1.0 (and early 2.0).
Tech twitter was absolutely losing their fucking minds over CloudFlare hosting this site, and were actively moving away to competitors. As much as it sucks to admit, this was likely not an empty threat, and happening in large enough numbers that they determined it was an impact to their bottom-line and that they had to "cut us loose".
Still, an absolutely cowardly move on Matthew Prince's part, and I think he could have offered up more resistance than he did. If people like him are actually our best hope in the tech industry, then we're fucked.