What we haven't heard about is whether or not the CAA is lobbying EASA to allow for a direct grandfathering of the current ICAO-compliant UK-PPL to the future ICAO-compliant EASA PPL.
The (proposed) conversion process for UK PPL to EASA PPL is set out in Part-FCL Annex 2. It's almost identical for the current process of converting a UK PPL to a JAR-FCL1 PPL.