HND to JFK Business Class Experience 787-9

Hi all, I have a pretty good upgrade offer on this flight for an upcoming trip, and am probably going to pull the trigger either way, but I am wondering what people’s experiences have been! Is there a way to tell if it’s the new flagship plane? Excuse my ignorance in this realm, I haven’t taken many long haul business class flights before😅 I saw a video about the new planes and couldn’t tell if all the planes have been upgraded or how that works. I saw the newer planes have a little privacy door and it would be super cool to have that. Thank you!