As I see it, it will come back in the future. MC don't have problem with money, he can make his whole family live without having to works... especially if they live in a small island where incest is fully legal. So, for me it wasn't just a rebellion against Patreon's ban (since it occurred few times after), but a full part of the game. It's still just an introduction, but for me it will be the justification of the ending.
MC fuck all his family, every one is fully aware of that and accept it... and that's where most of harem incest game (plan to) stop ; "thanks to you, don't hesitate to play my new game next month". But, it don't feel like an ending. What happen exactly ? How do they live this in their day by day life ? How can they live like that in a Western country ?
Even if in this country incest is legal and shared-couple morally tolerated, doing both at once will still be hard to live. "He sleep with his mother/sister", so what, as long as they both agree ? "He sleep with all the women in the house", so what, as long as they all agree ? "He sleep with all the women in the house, who are his mother and sisters", well, er... ok, it start to be weird...
But give them a strong reason to quit the country, while giving them a place where they can live their incestuous love in the open. And you have a real believiable end to the story. You can even add one or two updates that will describe this new life. It's not up to the player to imagine what happen next and how, the story give it to them.