Obviously, the situation on Maui has caused UA to alter its schedule subsequently. All the carriers are figuring out how the effects of Lahaina's destruction are going to affect traffic in the next couple of months and will be adjusting accordingly. They may have just removed the flight from the schedule (vs selling them out). You can still book flights to Maui, yes? Just not the ones you saw? If you bought the tickets you saw and the flights were cancelled, you would have been given option of refund or accommodation on remaining UA flights.

I see a 9am flight December 1 SFO-OGG and coach is pretty cheap. UA is running only 1 flight SFO-OGG on a Friday. That's a huge cutback from pre-fire.. One could count on a morning, midday, and late afternoon flight out of SFO to OGG in the past.