Is it for real that Bbak-ju and Yui aren't appearing in Iron Girls 3? ㅠㅠ

I liked Bbak-ju and Yui so much ㅠㅠ
Why are Yeon-woo and Ji-hyun suddenly appearing ㅠㅠ
It's a relief that Seol In-ah is at least appearing
If even Seol In-ah didn't show up, it might have been a disaster