I think Cassie is the "must" to return, at the least. She's the current champion, and I do hope they give her a badass looks and skills, more independent even tho Johnny's power lies within her.
When it comes to Takeda, in a possible tag team, or even only story matters, if Kenshi returns, he could be nice.
If Jacqui returns, I think she could be on her father's place, and while Kung Jin was nice to play in some ways (actually my brother even left Mileena to spam with him lol), I wouldn't care if he doesnt come back. As I said, Cassie is the only "must".
Unfortunately, I think these 4 are still too connected, so all of them may appear.
I don't despise any, but would rather see Cassie return instead of Ferra/Torr.