G.Fast is being rolled out as was originally intended - it was always going to be most economic and easiest for Openreach to start the rollout at the PCP's and then deploy it deeper in the network. This would have been the case even if they hadn't managed to increase the range of G.Fast - its just that certain people don't have the patience..
Unless I have missed a document at the announcement of G.fast I was under the impression the original idea was to put G.fast pods on nearby poles and underground, which would have
pushed deeper in the network as a stepping stone for FTTP. Then the idea was halted because of power issues i.e. who would power them, the cabinet or the customer. So the pole/underground idea was dropped and they moved them back to the PCP.