That's just false information. They didn't take any domain down. They stopped offering their CDN/proxying service to a customer. That customer is/was free to host their own content using their own or a different service. No company should be required to offer services to anyone and everyone unless they are the only option on the market. And cloudflare is very far from the only CDN on the market.
Unless I'm thinking of something else, it's not a domain registered through CloudFlare. The taken down site was using CloudFlare's reverse proxy service. IIRC, Matthew wrote about the incident in length.
I personally don't use CF for various reasons, but this site take down is not one of them.
