We ran some tests today that confirmed that h2c does seem to work.
localhost ~$ curl -I 'example.com' -H 'Host: example.com' -H 'User-Agent: Mozilla/5.0 (X11; Fedora; Linux x86_64; rv:49.0) Gecko/20100101 Firefox/49.0' -H 'Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8'...