Well, I mean, there's nothing stopping a random person from making their own game with the same characters, plotline and continue the story. From a legal perspective, I dont know if anything could be done by irredeemable, but Im guessing it'd be more time/money for him than what its worth. Also, Im pretty sure he wouldn't be able to remain anonymous if he wanted to pursue legal action.
From a practical perspective, I dont see any current devs just picking up and running with creating a carbon copy of this game and continuing it with a "mod". I think most devs want to create their own game and not just copy this one. Maybe Im wrong