If the AF arc continues after the rescue episode, I could see Lusamine becoming crazy, though maybe less from being evil all along but more the toxins intensifying what were controlled flaws beforehand to make her completely unrestrained. She goes from a bit overbearing and selfish but otherwise genuinely loving her kids to an abusive control freak, and her obsession with Ultra Beasts, which shown a moment of weakness last episode but she managed to overcome, utterly takes over her train of thought.
I honestly also could see them not saving her this time, IF they plan on dragging this out. I'm fine with the idea you've said as well. Maybe after Ash returns to Poni (to battle Hapu) is when they finally save her, assuming they battle her Totem Style Pokémon in the next few episodes, does anyone have a team that can take her out? I wonder how they'll handle her treatment? Maybe invite Bill to Alola?
Why did Serena have to change her style dramatically? She was OK in her old design.
She lost her first Showcase.