Quoting this (but couldn't figure out how to quote from a closed thread):
....the 787-9s are likely going to be for their international and domestic long distance routes (New York, Boston, Denver, and Dallas to HNL). I don't see them being used on west coast to Hawai'i routes That would mean downsizing from the twin aisle A330 to the much smaller single aisle 737-900 and Max 900

The only twin aisle Boeing product Hawai'ian operated was the 767 for a few years but those were replaced those by the A-330s. I don't see them going back to the older type.

Not very thrilled at the thought of spending 5 - 6 hours from the west coast cooped up in a 737 after having flown the route on DC-10s L-1011s (which Hawai'ian operated in the 80s) and even 747s.

1) AS/HA would be foolish to completely eliminate all wide body options from SFO and LAX as quite a few folks would simply take one of the UA planes; and,
2) What's flying downstairs on the HA widebodies to and from the West Coast? There may be plenty of profitable cargo, which means that profitable flights become losers if the aircraft is downsized.