There's the full story about 4/4 production on page 9 of the current Miscellany.

Essentially apart from the EU, 4/4's will be available unchanged.

For the EU, the 4/4 needs an ecu upgrade and be re-homologated, which will take time.

DaveW
'05 Red Roadster S1
'16 Yellow (Not the only) Narrow AR GDI Plus 4