Given that J'onn and Bioship are going along, my guess would be Mars.
Based on public profile and frequency of focus in episodes my guess would be Blue Beetle.
IMO, Nightwing not being the new leader of The Team is because he was also involved in the whole "Anti-Light" thing, whereas she was the most senior member who wasn't.
Raven, Timothy Hunter, her cousin Zach (although this would raise questions about s1), Black Alice, David "Sargon" Sergeant, Sebastian Faust...
I also wonder if:
spoilers:end of spoilers
The Prize is set in Year Nine or Year Ten. The lack of an indicator suggests that it takes place between the death of Bedlam and the epilogue montage but that doesn't fit particularly well. On the other hand, Artemis specifically references "her team" clashing with the villians for ten years, which could suggest either Year Ten or even Eleven?
Thoughts?