What do you think they'll do with the characters they reintroduced in Intergrade?

In Remake they reintroduced Weiss and Nero but, as far as I could tell, nothing in Rebirth even hinted at anything else. They're likely going back to Midgar for the Sister Ray and Hojo story beats. Unless deepground extends past Midgar, that return mission is the only chance I see them being anything but VR fights like Weiss in Intergrade