Very strange as I did emailed via openreach a few weeks ago of when will g.fast release to all isp's as a commercial rollout and they reply below:
OpenReach cannot answer this.
It's entirely up to the ISP if/when they choose to sell G.Fast. They are all able to sell it now, but many have choose not to yet.
Plusnet could sell it tomorrow if they wanted.
Back when FTTC was rolled out the likes of Talktalk didn't offer it for many months.
The trial is technically still ongoing. Pods in some trial areas aren't even live yet.
The commercial rollout has begun though, with lots of exchanges not in the trial having had G.Fast pods installed. Some of these are already live, before some trial areas.