Thanks for the clarification, when I got home this subject was on the Radio4 news for a while, then it became clear this was as you state speculation based on what was written in the USO Consultation document and/or his discussion in the DCMS meeting.
I guess when the results of those trials are completed BDUK will publish their findings about the viability and cost of how to provide +24Mb/s to the final 3%-5%.
PlusNet Unlimited Fibre 3Mb to 5Mb