I would like the leave the Scions behind. I don't think they were very interesting characters. The only ones I sorta liked were ARR Alphinaud, Alisaie, and the ShB recharacterization of Thancred and Urianger. The rest were duds to me.

I think one of the problems with the Scions is that most of them were holdovers from 1.0, which was written by different people, so the current creative team was saddled with characters that were already conceptually set, and it was hard to recharacterize them (with ShB's reintroduction of Thancred and Urianger being the only time they did that). I usually find the expansion side characters, like Aymeric or Hien or Gosetsu, to be more entertaining than the Scions. So I am interested to see what new, original party members the writers come up with.

If we were to bring some old characters along with us on a new journey, I did promise Aymeric to take him adventuring some time, but apparently his VA had a scandal which dooms careers in Japan and it is uncertain if he will get a chance to come back and voice the character, so perhaps we'll never see Aymeric again. I also like Gosetsu, but he is off enjoying his golden years and is on a pilgrimage.

I really liked Ramza from the Ivalice raid storyline, but sadly there is very little hope of him ever coming back, let alone becoming a party member.

I hope I never see G'raha Tia ever again, but given how he's the current writer's pet and how much he's been shoved in my face, I'm dreading he's gonna be back as a main in 7.0.