Dassa, thanks for your reply. What is your source for this info?
It is all publicly available on the Openreach All-IP website. The effects of copper stop sell at an exchange are detailed there.
What is less defined is what happens at the tail of the process where there are a set of customers who have been with the same provider on FTTC for a long time in locations covered by FTTP and show no signs of moving. I suspect that either there will be some form of cost differential introduced such that it becomes increasingly uneconomic to stay on FTTC or Openreach will simply give a withdrawal date (probably a couple of years notice) and terminate the service.
As others have noted there is an exception for low speed FTTC services but I suspect that that exception will not last very long, for both financial (why run two networks in the same area) and political (are less well off people not entitled to FTTP?) reasons.