What about Jean's boyfriend Glob Herman?
I very much doubt if adult Lorna appears it will be in the field taking orders from those about half her age. Then the question comes in does it make sense that she would be back at base taking orders from Magneto? That is not really necessary so then what? I guess we will have to wait and find out.
I don't think any adult will join the team. I do think an adult (Polaris in this case) might join the book's cast to interact with Magneto and probably work as an advisor to the team.
If one of them happens to be Sway or Petra I might actually pick up a few issues of this book
Jimmy Hudson would explain the claws and snikt solicit for issue 4.
“Have courage and be kind. Where there is kindness there is goodness, and where there is goodness there is magic.” ― Cinderella
If it's going to be a time displaced character, a big no thanks to Jimmy Hudson. That aside I'm not sure who I'd want. I love AoA Blink and Nocturne but I wouldn't want to see them taking orders from Jean either with all of their experience. Kymera would bring some much needed diversity to the team.
If Bunn went with Pixie I'd definitely be more interested. I'm somewhat interested for Mags with the potential of Lorna and Briar, but I'm still leaning towards passing since the O5 bore me and the book is going to focus on them.
I think Lorna is probably the reason Bunn said "2 or 3". She'll be part of the book's cast, but not an actual team member.
So that leaves 2 new team members and one supporting role.