I think the biggest effect this will have is to motivate rural communities to install fibre themselves. Once they ask for it from BT and are told, certainly just pay us x (massive number) thousand pounds they'll understand there is no point waiting in hope for openreach to upgrade their connection.
The actual physical side is fairly simple - fibre cable isn't very expensive and digging trenches through fields is much easier than in cities where roads and pavements have to be relaid and there are dozens of other services to avoid. You just need community involvement to dig and give the easements for free. B4RN is installing 1Gbps FTTH in North Yorkshire and Lancashire with this approach to great success.