Author here!

Biggest discovery when researching this was due to the ALPN requirement in Chrome [1], openssl 1.02 being required for ALPN, and the vagaries of Linux distro release schedules, Ubuntu 16.04 is the only LTS distro than can serve HTTP/2 to Chrome users.

When they're eventually announced, RHEL/CentOS 8 (Fedora already has the necessary openssl) and Debian 9 will also work. But right now Ubuntu is your only bet unless you want to build and maintain your own openssl. Which you don't.

[1] https://bugs.chromium.org/p/chromium/issues/detail?id=527066