All those concerned to see access to higher speed broadband rolled out to their area should contact their local councillors and suggest they ask their officers for a copy of the letter and to put the local plans on the council website so that local businesses, as well as local residents and possible alternative suppliers, can see them.
It is called "open government". Interestingly, open access to the plans appears to have been part of the small print of the EU approval of the BDUK framework for State Aid purposes.
Then the "real" work of securing local access can begin - remembering that not everyone actually wants it to happen. At this point I repeat my suggestion that those who are serious should join INCA - now clearly the most effective group in this space.
UPDATE: 16.00: See Jennifer's latest update covering which Councils have already made the data available