I know that there are explanations for seat availability by fare class showing less than a count of seats available on the seat map (for example passengers with tickets that have not as yet selected seats).
But how about the opposite situation......fare class showing more available seats then the seat map.

Here is a specific example. Flt 35 SFO-OGG on 7/31

Fare Class F9

Seat Map 7

Tried searching on this and couldn't find an answer. TIA