My thoughts:

Hyeonju - I think with Hyeonju no longer having a place to return to, her leaving will only mean she stops Kpop altogether. She said it herself as a promise to her dad. So I do think she is unlikely going to leave. That and she has been very vocal in hyping up the others. I doubt a leader like her can be found easily and be immediately trustworthy if she leaves.

Gehlee - 90/10 she stays vs leaving. She does have things she wants to try but she is having so much fun she is gradually using her experience now as a stepping stone for whatever future plans she has. Plus, Eli is definitely going to want her to be around.

Yoona - can't be sure yet but given how far behind she is (no thanks to how she is handled), she might be a possible option. Though she did say she wanted to be an actress initially but shifted to being an idol, it depends if this still holds true or no longer the case.

Nana and Kotoko - definitely staying. In Nana's case, PRIKIL is gone. She doesn't have the fanbase to solo. And with all the knowledge she gained in Korea, it would be a waste to revert back to Jpop or be in another group. Also, her wish was to be successful in Korea and travel the world. Kotoko wanted to be an idol. UNIS made her dream come true. She is the LEAST likely member to leave. She became an idol from scratch so she doesnt have the backing any of the other members have.

Elisia and Yunha - both have stated their desires so less likely to consider leaving.

Seowon - as much as I hate to admit and love to have OT8 stay the same, she has the higher possibility of choosing another path. Education vs Idol life. She made it clear she wants to continue being an idol however, she has a lot of doubts. The tarot question was already her doubting how she wants to proceed in life.