I usually assume longtime fans in a Lantern thread know what they're talking about, unless they are blatantly misrepresenting things. Guy is re-introduced to New 52 continuity in Justice League of America, right? Which I haven't read. If his history is still in some sort of canon, everything important should have happened in between. He starts as a reasonable man, gets tortured/brainwashed/brain damaged, begins recovery, , rivalry with Jordan, has altercation with Batman, experiments with other powers, falls in love with Ice, makes peace with former rivals. To me, these can be squished into the timeline so that some approximation of his history is intact.
But then I found that the Superman writers altered Hank Henshaw's history so that he wasn't responsible for Coast City's destruction. So it feels like anything can change.