It's F2, Y0, so 2 seats are for sale.

I also wouldn't go so far as to say extremely oversold. Airlines oversell flights based on the expected no show factor in the market. Compared to a business flight (e.g., weekday IAD-BOS or ORD-JFK), not many people miss their flight into or out of Hawaii if they can help it.

On a recent KOA-SFO that was zeroed out in all cabins, They admitted to me they oversold that flight by 5. We needed 1 volunteer (me).

So while things look good for your flight, don't expect them needing 20 volunteers or something.