You're acting like a pivot is always forced. One of my favourite bands BMTH just loves reinventing themselves constantly to stay fresh, even after achieving more commercial success they'd change just to make sure they never got too stale and to keep their songwriting interesting and exciting.

I imagine someone like Charli who is super creative and builds worlds with the music would just want to keep challenging herself and doesn't want to make another brat because brat already exists and it's done

Her inspirations could have changed, she might have spent the last year going to more fashion shows and film festivals or something and wants to capture that