Probably some IDs, maybe Ina or Kiara also. I doubt Sora even asked any of the JP holos, she hates imposing herself on them. Nene is probably involved though, she was in the conversation when Sora first mentioned a potential among us collab, Nene was giving Sora the contacts of some other JPs or something. So I guess it's up to who Nene might have invited, don't follow Nene so don't know who she's close with besides gen 5. Polka seems likely, Sora definitely knows her.
She said there were some surprising members. I'd love if there was a reuniting with some of the old guard of vtubers.
