Itch does not like it, if you try to skirt the rules. But they also do not like restricting creativity and freedom. I do not know the situation for the game you mentioned.
But all games that are adult games and accept payment are currently not indexed. No matter their content. This is because people that lie have started a dirt slinging campaign and made payment processors threaten to withdraw services entirely from Itch. For content that is ok on other platforms. Including Steam. There is no legal grounds for this. So those bigots bully companies. There is not really many alternatives for low cost payments internationally. So Itch just made it all invisible for the time being.
What Itch hosts and does not host is within in the chosing of Itch. Even if they write guidelines about it. It is not law and there is no rights involved to treat every game the same and have strict enforcement of guidelines. They do have several layers of how they chose to present content, according to my observations.
1 Promote it in the featured list. https://itch.io/games/new-and-popular/featured
2 Have it indexed in the discovery system. (Appears in search and browse)
3 Remove it from the discovery system.
4 Remove the game.
5 Remove the developer.
Adult games never get 1. 2 only happens if you set your settings to show it. All paid adult games currently got 3. 4 is banning the game, although you will find many complaints about so called bans, that are just removal from index. 5 fake accounts and actual law breakings get that. For payments, there is also the possiblity that Itch refuses the option to use Collected by Itch as a payment option. I believe that to have to do with taxes and risks and such things.