[pns]

See cloudflare blog post conclusion - they're quite aware it's hopefully unnecessary and possibly just a flair factor (their pun :) but may help prevent an attack ever so slightly.

"Hopefully we’ll never need LavaRand. Hopefully, the primary entropy sources used by our production machines will remain secure, and LavaRand will serve little purpose beyond adding some flair to our office. But if it turns out that we’re wrong, and that our randomness sources in production are actually flawed, then hopefully LavaRand will be our hedge, making it just a little bit harder to hack Cloudflare."

[tptacek]

You know, that, or actually fuzzing their proxy code.