I have also heard on the grapevine that if a 'European' type NPPL is approved then the medicals will have to be done by an AME.
Not true as far as the UK is concerned if the present proposals are accepted.
At the moment AMEs are not allowed to conduct the HGV type medicals called for by the NPPL.
An HGV medical is NOT currently needed for the NPPL. Only a declaration from your GP that there is nothing in your medical records that would prevent you from passing such a medical.