I think you have misunderstood the issue. Just because YOU did not use those services does not mean your data was not leaked. It means that other peoples data was not leaked on YOUR site, but YOUR data could be leaked on other sites that were using these services.
If this part is true, they're not vulnerable. Only data that was sent to CloudFlare's nginx proxy could have leaked, so if they only proxy their static content, then that's the only content that would leak.
The rest of their comment gives the wrong impression though, yeah.
The way it worked, the bug also leaked data sent by the visitors of the these "static sites": IP addresses, cookies, visited pages etc.