Well, here's my opinion on having someone who could be a Jacen Solo analog (strictly speculation! I haven't even read the reddit stuff!) have a dark side to light side redemption arc:
The biggest problem with the end of the EU series where Jacen went bad was how they had everybody give up on him turning to the light again, added with giving him just a tiny bit of ambiguity in his last scenes (selfish, protect-my-daughter-ambiguity, but still having him spend all his energy doing that instead of killing his sister when she left him an opening).
If they want to re-examine that arc, I think they should either show the darksider considering the option of turning good, want it, then reject it and embrace villainy so hard he becomes a sad nightmare, or show someone getting converted to the light and having to put up with the consequences for their actions, like life imprisonment, or execution.