Any plane with P+/PE seating will also have Polaris seating, so yes, booking a flight with P+ sold as a separate cabin will also "guarantee" Polaris seating (barring a last-minute equipment swap). I have a feeling we'll be seeing more hi-J 763s (already scheduled on EWR-OGG and been making several appearances as subs for regular 763s or various 777s) and/or internationally configured 777s flying to the islands.