To be clear (?), the European LAPL will replace the UK NPPL for flying aircraft within the scope of EASA airworthiness rules. You will not be able to fly an EASA aircraft with an NPPL.
To continue to fly an Annex II aircraft (out of the scope of EASA rules) in the UK post-implementation of the EU LAPL we presume the UK NPPL will still survive and be the licence to have. If one has a conversion from NPPL to LAPL then one presumes one will be able to fly an Annex II aircraft with the LAPL.
Confused?
Just guessing.
DGR / Secretary, NPLG Ltd