November 2015, Google said they would let us know if it is safe to go HTTP/2 with your web servers by the end of 2015. That never really came but they did discuss how there is no HTTP/2 SEO advantage later on this year.

This morning, Google on Twitter gave everyone official clearance to go HTTP/2. Google wrote:

So if you have been itching to go HTTP/2 and you were waiting for this, you now can feel more comfortable flipping the switch. Although, I know many of you have already done it, since it is backwards compatible.

Forum discussion at Twitter.