I really don't give af if they're just BBFs or If you want them to be girlfriends, bottom line Chie and Yukiko need to be together point blank period.
I'm not romancing Chie because how dare I, a MAN, get in the way of what is clearly peak Yuri. Chie 100% is gonna be the "Knight" that saves Yukiko cuz they gay and shit. I saw gay so i said gay. Happy Pride