Of course it depends on the writer but that's a boring answer
If the Luigi is a normal person nothing happens, the Justice League is too button-down for that. Maybe Jason (Damien in tow? Depending on who's writing he's still trigger happy) goes after them but stops at the last moment cause the rest of the bat family talks him down
If their tragic backstory made them a proper villain things get more interesting, but I still predict that they would do a The Falcon and The Winter Soldier style "you have a point but this isn't the way to go about it". The villain either refuses to repent and dies by accident/their own hand or goes to Blackgate forever. Whoever inherits Wayne Enterprises (last time it was Tim) makes some token changes and the arc ends on a note of "incrementalism good, radical action bad"