When Psychic Force 2012 rolls in, they ommitted Sonia, Brad and Genma, and when they appear again in Psychic Force 2, they don't get Story Modes. Canonically, what happened to them? Do they canonically die? Sonia, I can see her getting the end of the stick in any way she is involved, but Brad is not signified to have died in his story (and probably not Genma either), so do they just randomly Dropped a Bridge on Him?
Pretty much! Sonia dies in pretty much all modes, so there she goes. Brad got killed when Wong broke away from NOA, I guess. Genma either died or just went home.
It's also implied in Wendy's PF2 story that she is still looking for Sonia, and Wong makes no attempt to reveal Sonia's living status. So does this mean Sonia still lived, but is hiding, or Wendy was being delusional?
For one thing, she's not looking for Sonia, she's looking for her sister. Wong has to tell her that Sonia == Chris, because only he and Burn got to be canon for 2010. As far as Wendy knew, it was entirely possible Chris was still alive, even if she knew Sonia was dead. How Wendy is unable to recognize her sister...well, she's kind of an airhead.