I doubt that actual longhouses in Polynesia have balconies. They probably don’t have 2nd floors either. The longhouses I’ve seen in Hawaii don’t have either one.
Obviously, I wasn’t there, but I can speculate that they were trying to design buildings for the Polynesian Village that would resemble actual buildings on the islands of Polynesia, which don’t have balconies.
Darned if I know, but we ran afoul of that on our 2nd visit in '89 - back when we could afford to stay at the Poly. DH & I were looking forward to our lovely private balcony with a garden view.
Well, we did have a lovely view - garden, lake, and a corner of the MK -- from our 2nd floor fenced-in sliding patio door....