Now I would assume that for this to happen national authorities would no longer be in charge of issuing licences
I think a lot of people made that assumption but it is not correct. EASA write the rules; National Aviation Authorities use those rules to carry out their normal regulatory function which includes the issue of licences.
JAR–FCL 1.215 Class ratings (A)
(a) Divisions. Class ratings shall be
established for single-pilot aeroplanes not
requiring a type rating
Type (of aircraft):
All aircraft of the same basic design,
including all modifications except those
modifications which result in a change of
handling, flight characteristics or flight crew
complement.
All Types are listed in in the EASA Documents. Classes are generic groups of aircraft e.g. SEP MEP TMG etc.
I would have considered this to be fundamental knowledge for a FI