Is there a risk to hosting service if hot-potato site is using cloudflare?

Picture a politically hot website that might be subject to a DDOS attack. If that site is hosted at examplehosting.com and then uses cloudflare or another CDN, is the hosting service vulnerable to a DDOS attack on the site?

I do understand that the host could be discovered via DNS settings and attacked directly unless something was done to obscure the host IP address.