as far as i'm aware the prize fight rewards have been the same for as long as the game's been around. i'm curious where those people in the chat got the information from, but i guarantee they confused it with something else.
Yeah I know, but those guys are very convinced that the characters have changed. They say that the reward of the beo fights was weekend warrior, the one of filia windswept and for painwheel was firefly.
The character PFs have always been the same. I have dozens of Raw Nervs, Harlequinns, Parasite Weaves, etc to prove it.
There was a one time special PF a few months back that gave the top placers a unique relic that contained one of the newly released golds at the time. (Windswept, Firefly, etc) Otherwise they've never been in PFs. That might be what they were thinking of.
Yes, as @Cellsai has explained there was once a unique, special prize fight called Hot Off the Presses and the top reward for that was a unique, special relic called the Newly Minted Relic which contained the new wave of gold fighter variants. Before that update all characters had two variants at each rarity tier, but after this there were three golds for everyone but still two bronzes and two silvers.
This was most likely what the people quoting Weekend Warrior, Windswept and Firefly were referring to, albeit mistakingly.