It is worth noting that not everyone was excited for the push to HTTP/2.0. Poul-Henning Kamp on Why HTTP/2.0 does not seem interesting:
For instance identifying the standardized HTTP headers, by a 4-byte length and textual name, and then applying a deflate compressor to save bandwidth is totally at odds with the job of HTTP routers which need to quickly extract the Host: header in order to route the traffic, preferably without committing extensive resources to each request.
That was 3 years ago. I suspect there is enough momentum behind HTTP/2.0 now that Varnish will end up implementing it, despite concerns like this.