I think Brooke wins LCK. In the season preview they run at the end of the first episode, they show a clip of one of her confessionals where she says the line "I should not have come back". It follows the clip from this episode where she is crying and says she didn't want to come back if she didn't do better. But she is not wearing the same thing she was wearing in her confessional for this episode. The outfit she wore in this episode's confessionals was the same one she has had for the last 4 episodes. Now, they could have been done after the show was over in which case it wouldn't indicate anything. But more likely, they were taken during the break before they all went to Mexico.
The clothes she is wearing for the "I shouldn't have come back" confessional have not been shown before in any confessional, even the LCK ones. So, either it was done after the show is completely over, or it was done subsequent to her eviction and before the finale. But if she doesn't win LCK, why would they show a confessional in the finale? I don't recall them ever doing that. Usually in this coming episode, they show the winner of LCK as they join the others, but no confessionals from the losing chef. I know this is convoluted, but I think I'm right. Or not.