When browsing Cloudflare, or
some Cloudflare enabled sites you'll notice that network requests are HTTP/2.
Not all Cloudflare enabled sites are showing HTTP/2 requests. For example, hacker news right now still shows SPDY/3.1.
The Cloudflare homepage IS using HTTP/2 https://www.cloudflare.com/. Keep a close eye on their blog for a post announcing this.https://blog.cloudflare.com/
https://cdnjs.cloudflare.com is also now HTTP/2, which is the main improvement for me.