I don’t think it was primarily as wish fulfillment at all. I don’t think anybody’s wish includes imminent death, which is the only reason she’s getting that luxury. The luxury is very much presented as the lipstick on a pig of a situation, including frequent references to Katniss not enjoying it because of what comes next.
Our culture romanticizes the beautiful and the doomed, and has since Romanticism began. Katniss is nobly facing death and doesn’t enjoy the glamour and celebrity, but she has them anyway. It’s not Katniss’s wish fullfilment; it’s the intended reader’s.