Strange that in the ribble-linked document Openreach say
Existing customers will remain on the GEA-FTTC 40/15Mbit/s product variant which will be fully supported until alternative options become available.
With the arrival of new product options, Openreach will work closely with CPs and their customers to ensure a smooth transition away from the GEA-FTTC 40/15Mbit/s variant to an alternative suitable product variant.
Surely they would just have said that the product was no longer available?
Not that it matters, as the replacement is "up to 20Mbps".