It is a 1h 35m flight for goodness sake. Even if you are in F, you dont get much more than in the domestic Class J which is really a PY but still not international routes PY standard. What is the big deal with barely 2 extra inches on the pitch and seat width on such short flight? Dont expect you will get some premium drinks... and there is no meal served.
We have a MIA-JFK-NRT-ITM award booked a few weeks ago to travel next Monday. The NRT-ITM is in economy not even the Class J. But for a flight has only 1h 20m blocked time, who cares!