I don't know anything about the game proper, but any chance of anyone from anti-rain coming back?
In the recent CN update for Leva (UMP45)'s major event, we know that Robella (RO635), Soppu (M4 SOPMOD II), and Alva (AN-94) are present (Note; Soppu and Alva TL's I got from others, it might be changed when they're officially released) within the current story and have CG. ST AR-15 was also shown in previous trailers, but she hasn't made an appearance in-game just yet. As for some other members, AK-15 was teased in a previous livestream alongside AN-94, but their silhouettes we basically using their MOD3 CG's as placeholders. As for the last 2 members of AR Team, we have no idea at present.
Isn't the lore that the commander had to cut all contact with the dolls that worked with him for H&K? Which includes 416?
Yeah, he was effectively forced into the "Mephisto Agreement" that forbids extended contact or contracting with former Griffin T-Dolls, precisely because the bigwigs of the UNRC and Neo-Soviet Union are worried about how much pull the MC would have and how much of a danger he'd be just by virtue of having so many loyal T-Dolls ready to fight for him no matter what on hand.
Groza's allowed to stick around because she has memory issues so she can't remember anything from G&K, while having Suomi with him for even a short time gets him an email with a subtle death threat in it.